don't strip the project apps when running `ct` with just a root suite specified

this ensures the project apps are compiled to `lib/` instead of `extras/`

Add module directory to include path

Several projects use an include path relative
to the project's root.
file:compile will look in three places for the include
files:
The current working directory
The directory where the module is being compiled
The directories given by the include option

To prevent future mistakes like the broken string introduced in
cf66dfd6ba, put opening and closing " on separate lines in each
multi-line lopts string. This also allows for cleaner (smaller) diffs
when removing/adding a flag.

cf66dfd6ba introduced a syntax error in the modified lopts string.
Without the fix, you'll provoke a shell error when trying to complete
`rebar3 ct --<something>`.

add profile option to clean task

deduplicate default test set generated by `rebar3 eunit`

local install and local upgrade

add unstable install/upgrade instructions to readme

this ONLY attempts to deduplicate test sets that are generated by
rebar in the absence of any user specified tests

Rework README and CONTRIBUTING documents

Display error message when bad config is loaded

- The README is better targetted to newcomers and explains the basics of
  the project: what it is, why use it, how to get started, where to find
  more information. It looks less like a reference and more like a brief
  overview of rebar3.
- Whatever looks like a list or reference manual material is expected to
  be moved to the website
- Be clearer about the rebar3 project structure in CONTRIBUTING.md;
  explain how to write tests, how to structure code, and so on.
- Added contributing section on bug reports, feature requests, etc.

If a bad configuration file is submitted to rebar3 shell, display the
following error:

    ===> The configuration file submitted could not be read and will be
    ignored.

And keep going otherwise rather than silently failing.

While crash-fast is usually a good mechanism, the shell so far is very
tolerant of failures from apps to boot and whatnot, so this feels
appropriate.

Fixes #1019

check at runtime instead of compile time for `file:list_dir_all/1`

change detection of valid modules for `eunit`

convert 'app' to 'application' in eunit_opts to match cmdline args

`beam_lib:chunks(..)` needs a path to object code which, frustratingly,
`code:which/1` won't return for cover compiled modules. instead just
assume that if `code:which/1` doesn't return `non_existing` a module
is something we can run tests on

this is slower than the compile time check but i guess packaging rebars with
repos is still a thing and i think only the eunit and ct providers call it
anyways

when using the `--file' argument to `eunit' paths were being converted

into directory test arguments

upgrade bbmustache and relx

Remove triple brackets in bbmustache templates

Issues formerly were avoided by quoting atoms. Unquoting them created
unbalanced tags (`{{{name}}`) which were mistakes. This patch inserts
spaces to unconfused bbmustache.

upgrade relx to 3.12.0

Support old-style shell for rebar3 shell

merge overlay entries into a single {overlay, list()} for relx

Updates cth_readable so it supports dumb terminals

Unquote templates, add a warning instead.

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.