Add LESS that enables meta-p printing

IPython/html/static/notebook/less/cell.less

@@ -1,94 +1,101 b''
 div.cell {
     border: 1px solid transparent;
     .vbox();
     .corner-all();
     .border-box-sizing();
     border-width: thin;
     border-style: solid;
 
     &.selected {
         border-color: @border_color;
     }
 
     &.edit_mode {
         border-color: green;
     }
 
     width: 100%;
     padding: 5px 5px 5px 0px;
     /* This acts as a spacer between cells, that is outside the border */
     margin: 0px;
     outline: none;
 }
 
+/* Don't border the cells when printing */
+@media print {
+    div.cell {
+        border-color: transparent !important;
+    }
+}
+
 div.prompt {
     /* This needs to be wide enough for 3 digit prompt numbers: In[100]: */
     min-width: 15ex;
     /* This padding is tuned to match the padding on the CodeMirror editor. */
     padding: @code_padding;
     margin: 0px;
     font-family: @font-family-monospace;
     text-align: right;
     /* This has to match that of the the CodeMirror class line-height below */	
     line-height: @code_line_height;
 }
 
 @media (max-width: 480px) {
     // prompts are in the main column on small screens,
     // so text should be left-aligned
     div.prompt {
         text-align: left;
     }
 }
 
 div.inner_cell {
     .vbox();
     .box-flex1();
 }
 
 /* input_area and input_prompt must match in top border and margin for alignment */
 div.input_area {
     border: 1px solid @light_border_color;
     .corner-all;
     background: @cell_background;
     line-height: @code_line_height;
 }
 
 /* This is needed so that empty prompt areas can collapse to zero height when there
    is no content in the output_subarea and the prompt. The main purpose of this is
    to make sure that empty JavaScript output_subareas have no height. */
 div.prompt:empty {
     padding-top: 0;
     padding-bottom: 0;
 }
 
 div.unrecognized_cell {
     // from text_cell
     padding: 5px 5px 5px 0px;
     .hbox();
     
     .inner_cell {
         .border-radius(@border-radius-base);
         padding: 5px;
         font-weight: bold;
         color: red;
         border: 1px solid @light_border_color;
         background: darken(@cell_background, 5%);
         // remove decoration from link
         a {
             color: inherit;
             text-decoration: none;
 
             &:hover {
                 color: inherit;
                 text-decoration: none;
             }
         }
     }
 }
 @media (max-width: 480px) {
     // remove prompt indentation on small screens
     div.unrecognized_cell > div.prompt {
         display: none;
     }
 }

IPython/html/static/notebook/less/codecell.less

@@ -1,44 +1,48 b''
-div.code_cell {
+/* avoid page breaking on code cells when printing */
+@media print {
+    div.code_cell {
+        page-break-inside: avoid;
+    }
 }
 
 /* any special styling for code cells that are currently running goes here */
 div.code_cell.running {
 }
 
 div.input {
     page-break-inside: avoid;
     .hbox();
 }
 
 @media (max-width: 480px) {
     // move prompts above code on small screens
     div.input {
         .vbox();
     }
 }
 
 /* input_area and input_prompt must match in top border and margin for alignment */
 div.input_prompt {
     color: @input_prompt_color;
     border-top: 1px solid transparent;
 }
 
 // The styles related to div.highlight are for nbconvert HTML output only. This works
 // because the .highlight div isn't present in the live notebook. We could put this into
 // nbconvert, but it easily falls out of sync, can't use our less variables and doesn't
 // help the basic template when paired with our CSS.
 
 div.input_area > div.highlight {
     margin: @code_padding;
     border: none;
     padding: 0px;
     background-color: transparent;
 }
 
 div.input_area > div.highlight > pre {
     margin: 0px;
     border: none;
     padding: 0px;
     background-color: transparent;
 }
 

IPython/html/static/notebook/less/notebook.less

@@ -1,93 +1,100 b''
 
 body {
     background-color:   @body-bg;
 }
 
 @media (max-width: 767px) {
     // remove bootstrap-responsive's body padding on small screens
     body.notebook_app {
         padding-left: 0px;
         padding-right: 0px;
     }
 }
 
 #ipython-main-app {
     .border-box-sizing();
 }
 
 span#notebook_name {
     height: 1em;
     line-height: 1em;
     padding: 3px;
     border: none;
     font-size: 146.5%;
     &:hover{
         // ensure body is lighter on dark palette, 
         // and vice versa
         background-color:contrast(@body-bg, lighten(@body-bg,30%), darken(@body-bg,10%));
     }
     .corner-all;
 }
 
 div#notebook_panel {
     margin: 0px 0px 0px 0px;
     padding: 0px;
     .border-box-sizing();
 }
 div#notebook {
     font-size: @notebook_font_size;
     line-height: @notebook_line_height;
     overflow-y: hidden;
     overflow-x: auto;
     width: 100%;
     /* This spaces the cell away from the edge of the notebook area */
     padding: 2em 0 2em 0;
     margin: 0px;
     outline: none;
     .border-box-sizing();
 }
 
 div.ui-widget-content {
     border: 1px solid @border_color;
     outline: none;
 }
 
 pre.dialog {
     background-color: @cell_background;
     border: 1px solid #ddd;
     .corner-all;
     padding: 0.4em;
     padding-left: 2em;
 }
 
 p.dialog {
     padding : 0.2em;
 }
 
 /* Word-wrap output correctly.  This is the CSS3 spelling, though Firefox seems
    to not honor it correctly.  Webkit browsers (Chrome, rekonq, Safari) do.
  */
 pre, code, kbd, samp { white-space: pre-wrap; }
 
 #fonttest {
     font-family: @font-family-monospace;
 }
 
 p {
     margin-bottom:0;
 }
 
 .end_space {
     height: 200px;
 }
 
 .lower-header-bar {
     width: 100%;
     height: 0px;
     border-bottom: 1px solid @navbar-default-border;
     margin-bottom: -1px;
 }
 
 .notebook_app #header {
     .box-shadow(@notebook-shadow);
 }
+
+/* Hide the header when printing */
+@media print {
+    #header, #header-spacer {
+        display: none !important;
+    }
+}