Fix lints that have accumulated over time.
Apparently Android Studio just...stopped using lints. For no reason. I
had to upgrade to the beta version to actually get lints.
Update the album song layout to be more alike to other songs.
Recently I migrated the TextView in the album songs to use 48dp sizing,
like the other song views. However, this resulted in a lot of empty
space that felt off. Fix this by adding a light background to the track
number, which fills the room it takes up a bit more. It also hopefully
primes the track number to take an indicator once multi-select is
added.
Update the contribution information and templates.
The contribution information and templates were growing a bit stale,
given that they haven't gotten a refresh since ~1.3.0. This commit
reworks them to be more thorough and straightfoward.
