fix bug in table.py when specifying both column header text and color

row offset in table construction function was missed in case of specifying both text and color for column headers
table.py: added comments to previous change and fixed other bugs

1) Comment to clarify what we are offsetting and why.

2) Switched `rows' and `cols' in code to create header rows with
   color but no text, so our lists of empty strings have the
   right length.
table.py: clarified documentation
WIP: added some basic image tests for tables with headers. tests need to be tested
fixed table test script and images
fix bug in table.py when specifying both column header text and color

row offset in table construction function was missed in case of specifying both text and color for column headers
table.py: added comments to previous change and fixed other bugs

1) Comment to clarify what we are offsetting and why.

2) Switched `rows' and `cols' in code to create header rows with
   color but no text, so our lists of empty strings have the
   right length.
table.py: clarified documentation
WIP: added some basic image tests for tables with headers. tests need to be tested
fixed table test script and images
Merge branch 'patch-1' of github.com:bjcohen/matplotlib into patch-1
merge table tests down to one image file
fixed filename
Fixes legend.get_children() to actually return the real children of
legend while not including descendents who are children of other
objects (what would be grandchildren, great grandchildren, etc.)
Merge pull request #2755 from cimarronm/legend_children_fix

Fixes legend.get_children() to actually return the real children of
Merge pull request #2389 from bjcohen/patch-1

table.py: fix issue when specifying both column header text and color