Tests starting with a c are all now PEP8 compliant.
Most tests starting with a are now PEP8 compliant.
All tests starting with a p now PEP8 compliant.
Reverted PEP8 fix on bbox_tight test.
Merge branch 'pep8_on_tests'

Conflicts:
	lib/matplotlib/tests/test_agg.py
	lib/matplotlib/tests/test_backend_pdf.py
	lib/matplotlib/tests/test_backend_pgf.py
	lib/matplotlib/tests/test_coding_standards.py
	lib/matplotlib/tests/test_colors.py
	lib/matplotlib/tests/test_contour.py