Adds workingdir to executed_files
Adds exitcode to processes
Adds write_configuration

We now get more stuff from the database written by pytracer instead of
getting it from Python directly. This allows us to regenerate the
configuration from the database at any time.
Removes 2.6 from tested versions

sqlite3 on Python 2.6 doesn't handle embedded zeros correctly:
http://bugs.python.org/issue13676
Fixes typo
Merge branch 'regen-config' into 'master'