add cas support with a few tests
allow disabling of local logins.  In the instance where an .edu is using cas they may not want a user to be able to log in once the users credentials have been revoked in the system that feeds the CAS authentication server.  This is very optional
fix comment and remove url setting as it is not used.
FIX: Don't cast ids to ints, as user results have string ids.
Enable subscribing to notifications on start, instead of currentUser
change which was hokey.
documentation: add instructions on updating
Merge pull request #914 from Supermathie/sysadmin-docs

documentation: add instructions on updating
add email to share link description help
Merge pull request #892 from eriko/cas_support

Cas support
oops gemfile lock was missing from pr
Properly assign draft keys to Categories List view.
FIX: Regression, messages were hidden
documentation: merge & adapt suggestions from baus
Merge pull request #916 from Supermathie/sysadmin-docs

documentation: merge & adapt suggestions from baus
Add email to German share link description help.
Improve German translations.

This tries to improve the German translations in its context, making
them fit better in the layout, unifying different terms, fixing typos,
try to improve the readability and add some missing translations.
Merge pull request #917 from netzpirat/improve-german-translations

Improve german translations
FIX: Categories pill wasn't always being highlighted properly.
FIX: Hitting ESC while autocomplete is open shouldn't close the composer.
Show excerpts on Categories page