Implementing the bare bones of a generic "peer finder" framework. This
may or may not eventuate to something which can live in its own library
and be used by other projects. Might go hand in hand with Carries idea
of having a common UI to be shared among projects.
Fixes#240.
To make this easier, I added a script to aid in downloading icons.
Checkout F-Droid/tools/download-material-icon.sh for more details.
The icons are licensed under the CCv4 attribution license, which I
added a shout out to under "License" in the README.md.
