matplotlib Code

update annotation guide

With cairo /pycairo both at version 1.8.8, I'm still seeing crashes with paths
longer than 20000 points or so (tried the gtkcairo backend on Mac OS X). So the
path length check is still needed.

Fix offset_copy: the fig argument should be optional.

Fix offset_copy: the fig argument should be optional.

make default behaviour for order=3 match orders=0,1 for grid pts outside range of data.

add annotation_demo3.py

refactor Annotation to support arbitrary transformation.

update transform_scalar and transform_vector docstrings.

fix typo in previous commit

added order=3 option to interp