Merge pull request #8 from wallin/master

Handle null values + don't invoke digest cycle when not necessary
Version 0.1.6
Upgrade to bower 1.0.x
Cancel the auto-update timer when scope is destroyed
Upgrade to bower 1.1.x
Upgrade  NPM dependencies to latest version + add a "repository" field to package.json to make NPM happy
Version 0.1.7
Added support for am-format attribute for specifying date format (solves
amDateFormat filter added for displaying date formats.
grunt errors are solved.
amDateFormat tests added.
Merge pull request #12 from omerbasar/master

amDateFormat filter added for displaying date formats.
Fixed tests, indentation and made the new amDateFormat filter declaration minification safe
Added additional tests for the 'amDateFormat' filter
Upgrade bower to 1.2.x
Add changelog file
Version 0.2.0: new optional am-format attribute for am-time-ago directive, new amDateFormat filter
Fix an issue with tests failing on a different timezone
Add support for moment 2.2.x, AngularJS 1.2
Release version 0.2.1