fix the docstring for scale_docs to only strip whitespace at the end (the whitespace at the beginning is needed for alignment)
Fix #2338: pyparsing in 1.5.7's <<= operator doesn't return self, so we need to monkey patch it, too
Merge pull request #2344 from anshbansal/master

Fixed the issue of pyplot tutorial missing the show() command
Merge pull request #2334 from andreabedini/patch-4

Remove disabled code.
Merge pull request #2338 from mdboom/mathtext-pyparsing157-crash

issues with pyparsing 1.5.7 and python 2.7
Merge remote-tracking branch 'upstream/v1.3.x'