Fixed Content-Type of getFileContents()

Added getMimeType
Merge pull request #165 from marcelometal/mimetype

Fixed Content-Type of getFileContents()
handler_test: make test more reliable

Linux gives "text/x-sh", and not "application/x-sh".
Added support to redefine users of a repository

Thanks, @scorphus :)
Merge pull request #166 from ricardodani/master

Added support to redefine users of a repository