Moved the BrowserLoginActivity to te activities package
Added support for access token login to the browser login activity
Replaced getExtras().containsKey() with hasExtra()

If no extra's are provided getExtras returnes 'null' and thus
causes a NullPointerException when containsKey is called. This
change makes sure that hasExtra is used instead. And thus nolonger
crashes.
Merge pull request #26 from MMS-Projects/feature/accesstoken-login

Added access token support to the BrowserLoginActivity.