better support stacked bars
adapted header of figure2dot
improvements on axis locations
increment version to 0.3.2
updated ChangeLog
update figure2dot license to BSD
Add '\\' at the end of the line of each table data set

Apparently, when using tabled data inside certain environments in LaTeX (e.g.,
subfloat), the line breaks that mark the end of one data set are stripped off.
This is based on LaTeX's principle that whitespace doesn't matter.
The commit adds '\\' as line breaking character.