Removed the import from cbook into the matplotlib name space in __init__
and changed all cases of

from matplotlib import MatplotlibDeprecationWarning as mplDeprecation

to

from cbook import mplDeprecation
tweaked intra-package imports from cbook
Fixed background colour of PNGs saved with a non-zero opacity.
Merge pull request #1946 from tacaswell/mpldeprec_imports

re-arrange mplDeprecation imports
Have a workaround if a Python 3 user has pyparsing <= 2.0.0
Cleanup formatting of setup messages
Bug if MPLCONFIGDIRS is set
Switch agg backend to use pixfmt_rgba32_plain instead of pixfmt_rgba32, which fixes a problem with alpha-blending partially transparent backgrounds.
Merge pull request #1868 from pelson/alpha_background

Fixed background colour of PNGs saved with a non-zero opacity.
Fix position of rotated text in Agg backend
Merge pull request #1968 from mdboom/rotated_text

Rotated text element misalignment in Agg