abort/error: print backtrace, abuse templates, overhaul result/diag (macos not done yet)

ams: support building unit test programs on windows/linux/macos

git subrepo clone https://github.com/Atmosphere-NX/Atmosphere-libs libraries ...

subrepo:
  subdir:   "libraries"
  merged:   "07af583b"
upstream:
  origin:   "https://github.com/Atmosphere-NX/Atmosphere-libs"
  branch:   "master"
  commit:   "07af583b"
git-subrepo:
  version:  "0.4.0"
  origin:   "https://github.com/ingydotnet/git-subrepo"
  commit:   "5d6aba9"