Switch Perfherder to react-router
Use top-level of app as a cache for projects, frameworks, alerts data and compare data
Cleanup files and move constants to dedicated perfherder file
Remove angular-related libraries and bump up the neutrino entry and asset limits
contribute.json is intended for consumption via the deployed site, so
does not need to be in the repo root. Everything in `ui/` will be copied
to `dist/` so once moved, `contribute.json` no longer needs to be listed
explicitly - and with Neutrino v5 this will allow for even more
simplification later.