20201222

Add additional dlls referenced by by netstandard 2.1.

20200222-hotfix

Update SDL2 to 2.0.12.

20200328

Split mono.tar.bz2 from libs.tar.bz2.

20200222

Revert "Update SDL2 to 2.0.10."

This reverts commit 038ea7ffc67c42e46822a595971a1545e5e0d6c9.

20200202

Update SDL2 to 2.0.10.

20191004

Update cert-sync to 6.4.0.

20191003

Update mono to 6.4.0.

20190506: Update build platform to Ubuntu 14.04 and Mono 5.20.1.

Debian 7's package servers have been taken offline
and Mono 5.10 ships bugs that impact the AppImage
runtime.

20190316

Package mono and add directory structure to libs.tar.bz2.

20180723: Switch build platform to Debian 7.

This fixes a cursor rendering problem that occurred
on multiple platforms when running the Centos6-compiled
libraries.