Add ability to sort contents by date published in table
sort by date added, last seen, alphabetical (last seen is buggy)
updated tablesorter to version 2.11
clean up code, hide 'last seen' column
Get last PageSeen using annotate()
Removed print statement
added SourceLastSeen table (needs testing)
removed comment
put else back
merge with master
commented out ability to sort by last seen
Merge branch 'master' into sort-contents
default to sorting documents alphabetically
changed the word 'alphabetical' to 'name'
Merge branch 'sort-contents' of github.com:jenkliu/nbproject into jenkliu-sort-contents

Conflicts:
	apps/base/models.py
	apps/pages/views.py
	content/modules/dev/ui.filesview.js