Added methods to control theta position of r-ticklabels on polar plots
pep8 for backend_pdf.py
remove backend_pdf from pep8 test exclude list
minor code standard changes
minor code formatting
more informative exceptions for empty/not-existing images in
compare_images()
Merge pull request #2567 from megies/compare_image_exceptions

more informative exceptions for empty/not-existing images in compare_images()
Merge pull request #2549 from joferkington/add-rlabel-position

Add methods to control theta position of r-ticklabels on polar plots
Merge pull request #2459 from megies/pep8_backend_pdf

pep8 for backend_pdf.py
fixes issue #2482 and adds note about incompatibility between bbox options and animation backends
fixed a typo
fixed another typo
Merge pull request #2615 from vlsd/issue2482

Fixes issue #2482 and adds note in matplotlibrc.template