Update to Stats 0.0.5 & implement Blog timezone support

Closes #2141 

This incorporates WPComStats-iOS 0.0.5 bringing the new feature of single-tapping on a graph bar to see detail in a toast/tooltip-like UI.  This also corrects a long-standing issue regarding timezones interfering with the retrieval of stats.  Today now is today relative to the blog/site's timezone, not the local device.

Caveat: Timezone is in blog options and requires blog options to already be synchronized to the device.  If timezone isn't available then GMT is picked by default.  Also, timezone support in blog options is different if synchronized via XML-RPC vs REST.  I've included unit tests to account for these variances.

cc: @daniloercoli