Improve empty collection check in add_collection.
Add test for add_collection
Typo in docstring.
Only set 'consider' if no value was supplied.
Fix bug in _auto_legend_data which caused the vertex list to always be empty.
Fix bug in helper function which prevented the legend from avoiding vertices.

This bug was not triggered before because count_contains() was never
called due to the empty vertex list in Legend._find_best_position().
Add TODO note about marker extents and vertex overlaps.
Typo in docs.
Fix test failure (caused by corner case in np.concatenate).
Add new test for automatic legend placement to check that vertices are indeed taken into account.
Add FIXME comment.
Also use 'loc=0' in 'test_various_labels' to further test the new code.
Update lib/matplotlib/backends/backend_cairo.py
Fix itervalues -> values.  As reported by Massimiliano Costacurta in mailing list thread "BUG: RuntimeError: dictionary changed size during iteration"
add default savefig directory
replace tabs with spaces
explicitly missing key or empty str signals to use cwd
PEP8
Implement savefig.directory for tk gui
fix comment in gtk FileChooserDialog: does *not* remember last selected file/directory