fixed broken links in main/sidemenu when using server_dir '/'
use djangos named URLs and url-reverse instead of manually constructing urls
tiny docstring, import and trailing slash change
Merge pull request #1 from fonfon/master

Update to include several django-changes by Sunil and some url-changes by fonfon
Merge remote-tracking branch 'fbxat/master'
made actions.py more pep8 compliant; added one more check to verify that an action is within the actions directory; moved actions directory path into the settings instead of hard-coding it
refactored actions to use exceptions instead of return-values
raise module exceptions in DEBUG mode
moved firstboot handling to a firstboot middleware
also raise url-import and init-errors in debug mode
menu and submenu now also uses djangos named urls and url-reverse
Merge 'middleware' changes
removed all manual url prefix handling, we only use djangos url system now
moved context_processor from plinth.py to a separate file; removed two unnecessary context variables: 1) use cfg.main_menu instead of main_menu; 2) request_path is available automatically