Strip ":0: " from unknown type/function/behaviour warnings

* Only include `plt_apps` (defaults to deps) in a single PLT
* Update PLT when `plt_apps` (or deps) are changed or updated
* Print warnings for all dialyzer runs (not just `succ_typings`)

* Nolonger supress standard warnings
* Nolonger include race_conditions by default[1]

[1] http://erlang.org/pipermail/erlang-bugs/2014-July/004518.html

- The OTP app template now adds the supevisor
- The default apps_dir value does not contain the trailing '/' that the
  template index already added.

The first variable can be unkeyed and the provider will sub in the
variable name 'name'. Additionally, the built-in templates and
documentation have been updated so that 'appid' is now 'name' and the
alternative commands are shown.

This totally breaks compatibility with rebar2, and maybe it shouldn't
have.