First changes to make the cardproxy less smart.

The refactoring on the irma webservice has sparkled the realization that a too smart cardproxy app makes for a lot of duplicate work at the webservice and cardproxy app. The changes in this commit work towards an approach where the javascript in the browser is the "master" and the cardproxy app behaves more like a "dumb" cardreader. This has the additional advantage that it makes the user experience more consistent across smartcard reader devices.

Do note however that the current version is incomplete and mostly untested. I.e., it is work in progress.
Parse commands from website correctly
Use Inserted/Removed instead of Found/Lost
Cleanup and convenience functions
Handle PIN entry
SelectApplet not needed anymore
Shortcircuit if error
Fix eclipse warnings
New state engine
Dirty hack: detect card loss

We work around the fact that Android doesn't send notifications for lost cards.
Instead, we send a vacuous command to test whether the card is still present.
But, the vacuous command is protocol specific, so this makes the cardproxy too
dependent on the actual protocol in use.
Show feedback messages
Longer delay, no toats
Handle timeouts

And some small stability fixes
Show feedback image longer as well
Return to idle upon 'done' event
Stop reconnecting after 3 attempts
Back button first returns to idle
Fix wrapping of feedback
New layout for Nexus 7
Use sw600dp for better layouts