add missing comma in colors list

    resulted in first color being 'black#000000' causing errors
Merge pull request #56 from minrk/comma

add missing comma in colors list
make examples compatible with python3
Merge pull request #62 from stonebig/py3_examples

make all examples compatible with python3
fixing facet related scales
Merge branch 'facet-issue'
full theme_gray now independent of matplotlibrc