UserInterface fix threading derpage

*untested*

 + don't try to read bootanimations before IO finishes
 + don't call startActivity from worker thread

Patch Set 2:
 - removed import android.R
 + extracted the bootanimation install to Async inner class

Patch Set 3:
 + don't make calls to closed streams... duh :-/

Change-Id: Ib6a151b0bf767c6bd6011da31a0a27ab4c6bf3cb