Make interactive_usage a bit more rst friendly

All paragraphs are correctly aligned so that it can be shown
in rst viewers without problems.

IPython/core/usage.py

@@ -74,6 +74,7 b" At your system command line, type 'ipython -h' to see the command line"
 options available. This document only describes interactive features.
 
 MAIN FEATURES
+-------------
 
 * Access to the standard Python help. As of Python 2.1, a help system is
   available with access to object docstrings and the Python manuals. Simply
@@ -190,50 +191,66 b' MAIN FEATURES'
 * Auto-parentheses and auto-quotes (adapted from Nathan Gray's LazyPython)
 
     1. Auto-parentheses
+        
         Callable objects (i.e. functions, methods, etc) can be invoked like
-        this (notice the commas between the arguments):
+     this (notice the commas between the arguments)::
+       
             In [1]: callable_ob arg1, arg2, arg3
-        and the input will be translated to this:
-            ------> callable_ob(arg1, arg2, arg3)
+       
+     and the input will be translated to this::
+       
+         callable_ob(arg1, arg2, arg3)
+       
         This feature is off by default (in rare cases it can produce
         undesirable side-effects), but you can activate it at the command-line
         by starting IPython with `--autocall 1`, set it permanently in your
         configuration file, or turn on at runtime with `%autocall 1`.
 
         You can force auto-parentheses by using '/' as the first character
-        of a line.  For example:
+     of a line.  For example::
+       
             In [1]: /globals             # becomes 'globals()'
+       
         Note that the '/' MUST be the first character on the line!  This
-        won't work:
+     won't work::
+       
             In [2]: print /globals    # syntax error
 
         In most cases the automatic algorithm should work, so you should
         rarely need to explicitly invoke /. One notable exception is if you
         are trying to call a function with a list of tuples as arguments (the
-        parenthesis will confuse IPython):
+     parenthesis will confuse IPython)::
+       
             In [1]: zip (1,2,3),(4,5,6)  # won't work
-        but this will work:
+       
+     but this will work::
+       
             In [2]: /zip (1,2,3),(4,5,6)
             ------> zip ((1,2,3),(4,5,6))
             Out[2]= [(1, 4), (2, 5), (3, 6)]
 
         IPython tells you that it has altered your command line by
-        displaying the new command line preceded by -->.  e.g.:
+     displaying the new command line preceded by -->.  e.g.::
+       
             In [18]: callable list
             -------> callable (list)
 
     2. Auto-Quoting
+    
         You can force auto-quoting of a function's arguments by using ',' as
-        the first character of a line.  For example:
+     the first character of a line.  For example::
+       
             In [1]: ,my_function /home/me   # becomes my_function("/home/me")
 
         If you use ';' instead, the whole argument is quoted as a single
-        string (while ',' splits on whitespace):
+     string (while ',' splits on whitespace)::
+       
             In [2]: ,my_function a b c   # becomes my_function("a","b","c")
             In [3]: ;my_function a b c   # becomes my_function("a b c")
 
         Note that the ',' MUST be the first character on the line!  This
-        won't work:
+     won't work::
+       
             In [4]: x = ,my_function /home/me    # syntax error
 """