Warn on missing app/module and improve output

* Improve *.app file warning
* Rename collisions to clashes
* Output plt name before searching for apps/modules
* Warn when missing app/module - nolonger raise
* Nolonger ignore hipe application as will warn on missing modules
Add mix alias install

Can install with `mix install`
Relax elixir requirement to 0.14.0