pep8 fixes
added try except to check for valid iterable
reworked set_markevery docstring to bullet list
tidy up
pulled the markevery logic out of the main draw function.
pep8 fixes
CHANGELOG, api_changes.rst, whats_new.rst
DOC : transposed incorrect section title
Merge pull request #2836 from tacaswell/set_size_doc

DOC/ENH : get/set_size_inches
Merge remote-tracking branch 'upstream/v1.3.x'
PEP8 : making pep8 happy again

 - trivial line break
 - work-around for bug in pep8
   https://github.com/jcrocholl/pep8/issues/271
Merge pull request #2960 from tacaswell/minor_pep8

PEP8 : making pep8 happy again
implement quiver 3d

this fixes issue #1026
pep8 spacing
Revert "pep8 spacing"

This reverts commit 2db111899d2b679aa5f534ed1418d273f3dc19e7.
pep8 spacing and imports
Merge pull request #2739 from tacaswell/extent_doc

DOC : improved `extent` of `imshow` doc
Fixed parasite_axes.py bug where a list was expected instead of a generator.
Merge pull request #2962 from ocefpaf/axes_grid1_parasite_axes_py3k_fix

Turn generator into list in parasite_axes
axvline doc typo fix