Added tests for apk module.

Only one, really, but that's better than none!
Corrected icon location in template.

Whoops!  Forgot to fix that the other day.
Fixed debug output for database, and fixed tests.

Should have done this the first time!
Changed apk.go to use checkErr whenever possible.

No need for the log module there anymore.
Changed web.go to use checkErr whenever possible.

No need for log here either!
More improvements in test coverage!

Next stop: main.go !
Changed main to better support testing, finished settings!

apk, database, and settings now have full coverage!
Cleaned up error message on settings test.

What the title says.
Added tests for main and web.

89.0% is good enough for me.
Modified webpage to only display enabled apps.

Changed applist to select enabled apps or all apps, added a new div
for the empty store case, and added some CSS to keep it from looking
too ugly.

Also added a bunch of "// not tested" flags to remind me which code is
untested.