check for Python 3.2

in setup.py and init

treats unsupported 3.x < 3.3 like unsupported 2.x
reset readline after running PYTHONSTARTUP

should avoid conflicts between IPython and Python completions
Fixing bug #5607

Changed the method from extends to merge which merges the two arrays as
desired - With Freyert
don't ensure_ascii in JSON messages in Session
Fixed Issue #4012 Added Help menubar link to Github Flavored Markdown doc
Better lessc detection/handling.

* lessc@1.5.0 now invalid
* more help if lessc not found
Merge pull request #5633 from ahmadia/improve_no_lessc_error

Provide more help if lessc is not found.
Merge pull request #5613 from nilenoether/fix-5607

Fixing bug #5607 - Some shortcut missing from help reference.
Merge pull request #5630 from onceuponatimeforever/4012

Fixed Issue #4012 Added Help menubar link to Github markdown doc
Merge pull request #5582 from minrk/pythonstartup-readline-sad

reset readline after running PYTHONSTARTUP
Merge pull request #5500 from minrk/check-3.3

check for Python 3.2
Merge pull request #5628 from minrk/no-ensure-ascii

don't ensure_ascii in JSON messages in Session
Fixed Issue #5531 -- Re-arranged placement of shortcut info in keyboard popup

Users were confused on how to use keyboard shortcuts because the pop-up
window documentation was confusing. The shortcut information is now arranged
in a clearer way; the help_indices have been changed.