Modified ipython banner

This is a squash of all the commits found in

    `https://github.com/ipython/ipython/pull/8773`

 - updated banner
 - updated banner again
 - fixed type
 - modified ipython banner
 - attempt at fixing rebase issues
 - modified ipython banner
 - fixed git screwup
 - updated banner
 - updated banner again
 - fixed type
 - fixed accidental deleted gui_reference restoration

IPython/core/usage.py

@@ -325,19 +325,15 b' The following magic functions are currently available:'
 
 """
 
-quick_guide = """\
-?         -> Introduction and overview of IPython's features.
-%quickref -> Quick reference.
-help      -> Python's own help system.
-object?   -> Details about 'object', use 'object??' for extra details.
+quick_guide = "Type '?', '%quickref' or 'help' for help, and 'x?/x??' for object details\n"
+
+gui_note = """\
+%guiref   -> A brief reference about the graphical user interface.
 """
 
-default_banner_parts = [
-    'Python %s\n' % (sys.version.split('\n')[0],),
-    'Type "copyright", "credits" or "license" for more information.\n\n',
-    'IPython {version} -- An enhanced Interactive Python.\n'.format(
-        version=release.version,
-        ),
+default_banner_parts = ["Python %s\n"%sys.version.split("\n")[0],
+    "Type 'copyright', 'credits' or 'license' for more information\n" ,
+    'IPython {version} -- An enhanced Interactive Python.\n'.format(version=release.version),
     quick_guide
 ]