Also expose it in rebar_api

Previously dialyzer stored the project PLT in ./build/, which meant the
same PLT was used for all profiles. This could mean partial rebuilding
of a PLT when switching between profiles.

It is not convenient for everyone to handle unmatched_returns and
underspecs warnings. Extra default warnings are removed to match
dialyzer's behaviour.

Previously dialyzer would crash when not doing success typing analysis.

When dialyzer_plt_warnings is false no warnings should be returned when
updating a PLT. Previously any callgraph warnings would be returned when
updating a PLT regardless of the get_warnings option.

erts.app was introduced in R16B02 so read all beam files from the erts
ebin directory if erts.app file does not exist.

Fixes cases where dialyzer warning might include a `~` causing printing
to console to fail with `badarg`.

code:lib_dir/1,2 can return archive directory for rebar escript archive
applications, rather than the application's directory in the project.

Add dependencies not listed in `applications` to `dialyzer_plt_apps`.

Adds a base plt per OTP version that is stored in $HOME/.rebar3/. The
base plt is copied to new projects that don't have a plt for the active
OTP version. Modules are added/removed to the project's copy based on
the project's .app files.

* Add description
* Make configuration constitent (prefix with dialyzer_)
* Make printed info consistent

* --update-plt=true|false (false skips updating plt)
* --succ-typings=true|false (false skips success typing analysis)

Try to automatically detect all application dependencies when `plt_apps`
is not included in `rebar.config`.

Note that this will not follow `runtime_dependencies` in OTP
applications. This can be resolved by adding any missing
`runtime_dependencies` to `applications` in the .app.src file or
including `plt_apps` in `rebar.config`.

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