Fix image paths in non-index markdown files

Fixes #138
Added a fix for Python2.6
Initial release notes
Updated classifiers for PyPI
Merge pull request #151 from d0ugal/master

Updated classifiers for PyPI
Merge pull request #149 from d0ugal/release-notes

Initial release notes
Merge pull request #148 from d0ugal/image-fix

Fix image paths in non-index markdown files
Support multiple template directories

theme_dir is now a list which contains the user provided directory if
given plus the packaged theme directory.

Fixes #129
Improve the tox coverage output
Updated notes
Merge pull request #145 from d0ugal/template-override

Support multiple template directories
merged before pull request to sync with upstream