Disable switching step when file upload is in progress.
Refactoring of fileuploader

* Handles cancelling of uploads
* Visualization of currently being uploaded files
Implement cancel all uploads button

Now displays pending uploads.
Don't change step while upload is in progress.
Move themes to themes script
Make the version of gettext be more flexible
Add marks for inserting glclient custom build styles
Using build keyword makes grunt a sad pig :(
Go for other route
Fix typo
Merge pull request #65 from globaleaks/bugfix/progressbar

Bugfix/progressbar
Merge branch 'master' of github.com:globaleaks/GLClient into devel