Refactored repo update to stream apks from network -> jar file reader ->
xml parser -> database. No longer build up large lists of app metadata
to save. Saves memory, but is MUCH slower.
Does sig verification properly, but does it at the END of the process
and DOESN'T ROLL BACK on failure.
Quick and dirty benchmarks show an increase in time from ~25 seconds
to ~30 seconds on my Nexus 4 with Android 5.0. This doesn't seem so
bad to me, for the tradeoff that people on low end devices can actually
update now.
Also, as @eighthave pointed out, if we are able to stream the download
directly from the internet, then that time will drop to essentially
the time it takes to download the index.
b989ef3ecc