Replaced underscore by lodash.
Removed underscore altogether.
Improved our timezone adaption code because it would yield incorrect results (& break tests) on Dec 31st and Jan 31st between 23:00 and midnight.
Added a comment for a common cause of failure
Trying to make the time zone quirks test more robust wrt. different time zones :-/
Now creating the moment in UTC - this allows to apply arbitrary formatting of the input
UTC creation behaves the same way as moment creation... thus:
Revert "Now creating the moment in UTC - this allows to apply arbitrary formatting of the input"

This reverts commit 1dc5d75b0d529030aabd4f0c2c38fea4365c40a0.
Now the moment in production code is directly created with timezone as well.
Joined the new moment tests with the already existing moment tests.
Moved persistence tests to the persistence test directory.
Moved sympaTransformer test to the groups test directory.
Merge pull request #560 from NicoleRauch/master

Removed underscore, improved date&time handling