install project app plugins after discovering them not before

only apply default and prod profile to dependencies

Fix windows stuff

only need to compare ref and not ref+url in git resource

warn if the directories `eunit' or `ct' show up in `src_dirs'

- robocopying a directory into another directory recursively expects the
  directory name to be properly mapped onto the destination, otherwise
  all the files are copied into the given path. This patches things so
  a directory-to-directory robocopy works as expected in a linux mindset
  so tests pass
- the test for canonical paths didn't expect a windows environment at
  all; the test (and library) is modified to be consistent in that
  environment: always with a native format and with proper support of
  drive letters.

contributors -> maintaiers in template app data

if these directories actually exist they'll be added to the path ahead
of the release/standard distribution directories and they'll break eunit
and/or ct execution

fixes #950

hex.pm is now using maintainers instead of contributors in metadata.
Templates should be updated to reflect it.

Allow bootstrap to pick up existing Hex cache and deps

allow ct suites to be specified at root of project (or root of app)

convert ~> versions to highest matching

Bump cth_readable to 1.1.1

This fixes a typo that could cause failure in some test runs.

Upgrade relx to v3.11.0

This detects existence of Hex registry at
$HOME/.cache/rebar3/hex/default/registry and skips "rebar3 update" step.
It also detect presence of bootstrap dependencies in _build/default/lib/
and skips fetching them.

Plugin templates

this allows repeated test suite names across apps without conflicts

previously rebar3 dropped suites declared at the root of the project (via
`--suite=whatever_SUITE' probably) and warned. this was because the compiler
would recursively copy and compile everything in the directory indicated by
the test suite. this changes the copy mechanism to only copy erl source files
and directories that end with `_SUITE_data' into the `extras' dir in `_build'

This lets a plugin define templates to be loaded:

    $ rebar3 new
    ...
    proper (plugin): A basic PropEr suite for an OTP application
    ...
    $ rebar3 new help proper
    proper:
            plugin template (...)
            Description: A basic PropEr suite for an OTP application
            Variables:
                    name="suite" (...)
                    ...
    → rebar3 new proper fakesuite
    ===> Writing test/prop_fakesuite.erl

In this case, proper is a fake template file I've put by hand in
_build/default/plugins/rebar3_proper/priv/<somename>/, meaning it will
only work as far as it's called from the project's root.

The priority order of plugins is now .config > plugin > built-in, such
that someone could ensure plugins do not crush their own private
templates, but also that custom or plugin templates do overtake built-in
ones. It used to be Built-in > .config only.

Templates are searched for recursively in the priv/ directory of
plugins.

support temporary cdn change with HEX_CDN os var

Fix wrong relative path resolution

A bad template index does not crash; shows warning

Tests both absolutes and relative paths.

Add support for total code coverage

This should fix #955

The test is implicit as a bad index previously silently crashed rebar3.
By adding the bad index to the `new` suite's files, we can show that
things keep running.

symlink mib hrl output in apps `include' directories

upgrade certifi to latest release

this restores compatibility with rebar2 and erlang.mk

fix tupple merging for realsies.

Full rewrite, code should be understandable now.

Tup merge tests