bug:1648729
print warning if a requery is attemped on main thread
bug:2459293
browser death because of NoSuchElementException. don't use iterator
to march thru the ArrayList. use old style for() loop.
bug:1609474
don't allow downgrades of databases
other stuff
use LRUcache to maintain statement-cache in SQLiteDatabase
Change-Id: I3a42022162f4dfcc75f7d0cfcad8f20f1d193249
20f549fd2f