Retrieve yogurt_session via the client's API instead of a cookie
Remove previous implementation of getting yogurt_session from cookie
Add JSON shim to payload
Fix bug with delete on IE8
Update Grunt tasks
Update README
Remove copy:ymls task from build step
Force build.number for the EasyXDM build step

Now payload can be hashed properly,
with same hashes been produced on different build locations.
Update README
Add karma-coverage plugic
Configure karma-coverage plugin
Ignore spec/coverage directory
Change cookie duration from 1 week to 1 month
Add 'no_images' parameter on beacon when images are disabled

Server needs this parameter to server a proper Javascript reply.
Else the returned gif value woulf be parsed as Javascript resulting
in a parsing error, which would in turn break the client's flow.