This moves all logic for setting up the local fdroid repo to its own
IntentService. That makes it much easier to interact with since things can
just use the static helper method to request it to update, and it'll do the
right thing.
The webserver was totally broken since nanohttpd had changed so much since
the swap webserver was implemented. This syncs up with the sample file and
gets rid of our hacks. The only differences now are the stuff that is
removed since it is totally unused in F-Droid. This also adds a full test
suite.
this actually closes#248
"full" is the original F-Droid app with all the features. It should still
build the exact same app after this change. "basic" is the smallest
version of F-Droid possible. It does not yet build, nor work.
