Update nn.js

Change the long date format, so that it follows the most common Norwegian system for dates (DD.MM.YYYY). Ref. http://en.wikipedia.org/wiki/Date_and_time_notation_in_Norway.
Update nn.js

Update test for nn
removing extra s in get() and set()
Added unary + operator to ms, days, and months in Duration constructor
when building internal representations
Added tests that check against string initialization of Duration
parameters
Closes #968
Split string value tests into their own test
Moment, Duration and Language objects now have constructor property
Merge pull request #979 from chall8908/develop

Fix for strange Duration behavior when using strings for values
Merge pull request #978 from icambron/extraneous-s

removing extra s in get() and set()
Merge pull request #966 from mechuwind/patch-1

Change the Norwegian nynorsk language configuration to follow the most common date format
grunt zones with TZ and zone.tab
Fixed a few comments
Merge pull request #983 from ichernev/improved-grunt-zones

grunt zones with TZ and zone.tab
Merge pull request #982 from ichernev/fix-prototype-constructor

Moment, Duration and Language objects now have constructor property