* remove partial support for ct `test_spec` until it can be done properly
  and warn if `test_spec` is present in test opts
* use new compiler functionality to reduce complexity of provider
* reduce command line options available to those that can be
  supported properly

* only try to cover compile directories that actually exist
* recover from failures where source files don't contain required
  attributes for cover compilation and print warning

at the cost of some SASL warnings this prevents rebar3 from terminating
processes when reloading their code before running tests

prevents code reloading by temporary marking of rebar3's ebin dir
as sticky during code refresh

* modify compiler interface to work on either application objects or
  directories containing source files
* compile all sources in `src_dirs` to the application `ebin` dir and
  all sources in `extra_src_dirs` to a directory mirroring it's
  position in the app's `_build` directory. for example, `apps/foo/more`
  would compile to `_build/default/lib/foo/more`
  for `extra_src_dirs` in the root of a project with multiple
  applications (so orphan directories that don't "belong" to an
  application) compile to `_build/default/extras/more`
* copy directories specified in `extra_src_dirs` into the `_build`
  directory so tools like `ct` and `xref` that expect source to be
  in a particular location still work
* clean compiled artifacts from all `extra_src_dirs`
* alter `eunit`, `ct` and `cover` to work with the new directory
  structure
* billions of new tests

This reverts commit 9d82215296.

fixes #872

removing the  /utf8 flag and using the the exact utf-8 value in bytes to make it compatible with compilers <17

Fix for issue #859 - unicode rendering of deps tree based on PR #865
modified PR #865 to the /utf8 flag indicates this is supposed to be a UTF8 string.

This passes the directory to the option to ensure it works with more
than configs at the root of the project.

Uses global rebar config to see if user wishes to disable ssl verfication.
If {ssl_verify, false} is present certificates will not be verified.

prior to running compile and compile prehooks

This reverts commit dde60d491f.

profiles are for

This commit replaces the method of upgrading by unlocking all transitive
deps by one that utilizes the parent element of each app to only
unlock transitive deps of children of the top level deps being upgraded.

Additionally the run function of upgrade_SUITE is modified to only create
the mock updates before the upgrade provider is run, instead of before
any provider is run, which would cause improper behavior in install_deps.

The list of applications in the relx config section could contain
tuples. The tuple will either contain a version constraint for the app,
the start type of the app or both.

This fix silently expands `{shell_apps, [Apps]}` to support the same
format.

The current code could not cope with missing dependencies, as they would
prevent the rebar3 app from loading or properly building its config,
which prevented the log state from being carried along with default
values. This in turn would turn in an escript-level error that
obfuscated the true source of failure.

This patch bypasses the whole state setup and logging macros and logs an
error message manually when a dependency such as crypto or SSL is
missing from the Erlang install.