Detect if iptables supports comments

Seems some iptables shiped with ROM don't support comments.
This patch allows orWall to detect this kind of problem, preventing
comments to be added to the rules.

This should allow rooted stock ROM to run orWall. Tested on genymotion
4.2.2 successfully.
New activity and related style (transparent)

This activity allows to do basic checks in background, while main
activity will just wait for it to provide results.

This new activity will most probably get extended.
some refactoring
Refactoring and push stuff to background activity

This allows a smoother app, better experience, and some code cleanup.
corrected manifest
Better logs, added new check for orbot install
ensure the value is correct for comment support