fixes pep8 and pylint errors and rename mitx->edx
Fixes broken imports in checker.py
fixes launcy not working with Dir.chdir
Fixes bugs in documentation and improves it.
fixes pep8 and pylint errors
Fixes bugs in documentation (rst format)
adds test for doc generation
adds changes to changelog
makes tests for sphynx doc generation  not to run browser
removes reference to removed module in docs
Merge pull request #163 from edx/alex/fix_rake_doc

Alex/fix rake doc