Allows `pre_hooks` and `post_hooks` to fire for the `edoc` provider.

Somehow swapping the tty handler once more fixes everything. I guess we
were missing a step somehow.

The sys.config loading in the shell command did not implement recursion
and thus processed the file different from a `erl -config cfg/path`.

Instead of reading every time that rebar_dir:global_cache_dir/1 is
called

When an app contains one of the modules we can't afford to get upgraded
without breakage (i.e. erlware_commons, providers, getopt), skip
reloading that application from the rebar3 agent, such that it can keep
on working in subsequent calls.

Blacklisted:

- erlware_commons (broke on ec_cmd_log)
- providers (core to functionality)
- cf (useful to not explode on colors)
- cth_readable (only used for CT suites, but incompatibilities may break
  whole runs)

I've tried to compile project with git in .app.src vsn
Project was tagged as 1.0.0, but resulting .app vsn becomes 1.0.0+build.6.reff0aec24

```git lg
* f0aec24 - (80 минут назад) Fixed ct — Kozlov Yakov (HEAD -> master, tag: 1.0.0, origin/master)
... 5 commits before
```

```
$ git log --oneline --no-walk --tags --decorate
f0aec24 (HEAD -> master, tag: 1.0.0, origin/master) Fixed ct
```

I've found that `HEAD -> master` doest match pattern in [rebar_git_resource](https://github.com/erlang/rebar3/blob/master/src/rebar_git_resource.erl#L204)

This commit moves the handling of distribution config and starting out
of rebar_prv_shell and into rebar_dist_utils. The module is able to
handle standard config options and boot a distributed node mode. This
could be used in plugins (once it is exposed) and other providers like
CT.

Configuration is also expanded so that options like:

    {dist, [{sname, atom()}, {name, atom()}, {setcookie, term()}]}

can be used and will be handled as a default. The config handler
supports similar terms from the command line being parsed in if the
calling provider supports them.

A test suite is added for configuration handling.

Unsure if this should be a final supported format or if we should
support other ways to match instead.

This is a demo to solve the issue hilighted in
https://github.com/erlang/rebar3/pull/1072

By default, the dependency only handled versioned packages and top-level
source dependencies, and locks were being ignored.

This patch makes it so locks and package deps are being considered,
generating full-blown path lists.

Should fix #1117

Following suggestions from @psyeugenic, this code terminates and waits
for the termination of the port handling IO before booting our own,
which should get rid of annoying warnings.

We also allow for the failure to shutdown the user worker under
kernel_sup, since it is likely not there anymore in many scenarios,
preventing crashes.

Allows overwrite the default cache directory using the environment
variable REBAR_CACHE_DIR.

add definition of 'COMMON_TEST' macro to eunit provider

This reverts commit 4c32c52b55.

The idea is that given we accept arbitrary config items for CT, we
should similarly be able to pass unsupported options and keep things
running.

However for unsupported options, a warning is very useful to have.

This patch adds support for short options in the eunit provider.

Add more version constraints

Allow for any number of whitespaces after compairison opperator

Improve updating and error printing

Fix failing tests

Replicates `erl` behaviour.

Changes to how hex or packages may work in the future will necessarily
bring changes to the format of lock files.

This commit adds an optional framing for future lock files of the form:

    {Version, LockList}.
    <Whatever consultable attributes>

This format is supported such as the LockList is the current lockfile
contents, and will never have more information than it currently does.

Attributes can be whatever and are currently undefined.

Rebar copies will be able to:
- Keep using the core locklist (which avoids breaking the last year or
  so of community libraries using rebar3)
- Warn when it runs an outdated copy in comparison to the lock file
- Automatically rewrite lock files in the format it supports
- Augment or parse files in a version-specific manner.

This changes the usage interface slightly, but is backwards *and*
forwards compatible.