including link to activity itself into sent mails
Merge pull request #598 from NicoleRauch/master

Bugfixing
new module: notifications for sending information based on things happening
Merge commit 'e786ac18bc8ed63049e62ef823a3b7a427ca2dfc'
introducing chai's "exist" assertion - removing !! to be true for truthiness
Merge pull request #599 from leider/master

Notifications!
it is now possible to subscribe to events of only one group
forgot semicolon :(
Merge pull request #600 from leider/master

it is now possible to subscribe to events of only one group