Merge pull request #646 from nelenkov/dev

removed old Admob account UI; ignore quota exceeded errors
Merge pull request #647 from nelenkov/dev

updated changelog and bumped version for alpha release
Merge pull request #648 from nelenkov/dev

try to send less AdSense API requests
do detach/attach for LoadBitmap
detach/attach LoadBitmap task
Merge pull request #651 from yulin2/dev

refine pr for AndlyticsProject/andlytics#649
open redirection URL in browser if not dev console