Adapt arch string to versioning scheme changes (>= 17.x)

As mentioned in the OTP documentation, licensed customers may use
patched OTP installations where the otp_patch_apply tool adds a '**'
suffix as a flag saying the system consists of application versions from
multiple OTP versions. When we get such a version string, we drop the
suffix, as we cannot obtain relevant information from it as far as
tooling is concerned.

bootstrap now accepts --help usage flag

fix for #314 (rebar shell somehow blocks using io:format in gen_server handle_call)

Conflicts:
	THANKS

ensure any processes with a reference to an old user process as their
group leader are updated to use the new user process. this introduces a
slight delay at startup as the system must wait for the new processes
to be registered. there is a max wait period of three seconds (before
the shell command gives up and throws a timeout error)

fixes #314 ("rebar shell" somehow blocks using io:format in gen_server
handle_call)

rebar's beam files are actually compiled by bootstrap's call to
make:files/2, so warnings_as_errors in rebar.config isn't really used.

* fix overlong lines
* where appropriate use %% instead of %

Moves ct_extra_params to the end of the generated ct_run command.
This allows users to pass commands to the underlying emulator
using -erl_args. The included rt test demonstrates that it is
possible to pass an addtional option to ct_run and -erl_args at
the same time. Finally, the test executes in regular and verbose
modes because rebar constructs the ct_run command differently in
verbose mode.

This reverts commit 07e2232847baa634b7d09bdb87dafda6c6bcc4a4, reversing
changes made to 37cf470ae9.

Quote include/lib paths

Fix #249 (erlc regression)

Add gen_event template

Switch template instructions

Add code coverage analysis functionality to `qc'

Partially revert naming changes introduced in 93689703c1:
CoverageModules -> FilteredModules
get_coverage_modules -> get_matching_modules

Having the name "coverage" meaning "filtered/selected modules" can be
confused with code coverage.

- Use `cover' with QuickCheck testing
- Reuse the `cover_*' rebar.config options
- Refactor cover-related code to separate module (`qc_cover_utils')
  for use with both `eunit' and `qc'

This reverts commit 3297ffec2c89c6b7135165b4bfaeaeb07167c33c, reversing
changes made to 0401debb3c.

Move include/rebar.hrl to src/rebar.hrl

ct fixes

Add REBAR to environment before executing hooks

Some optimisation/refactoring using stdlib's functions

Add qualified name tests specification (see #118)

Fix #176

Add support for the Perforce VCS client via the "p4" tool

* Corrected regexp: `[x|y]` -> `[xy]`.
* Used an re:replace/4 option instead of multiple IOlist functions.

Namespaced types: fix build for 17.0

We use namespaced_types option to choose between dict() and dict:dict() types.

REBAR will be set to the rebar binary which was executed and runs the
builds. Enables the use of the same binary for rebar invocations as
part of a pre or post hook like so:

    ${REBAR} escriptize

erlc: replace if expression with case of

Motivated by the bug fix in 2c4d7d1.

erlc: fix typo in update_erlcinfo/3 clause

The combination of changes to rebar_erlc_compiler, and the fact
that erl_first_files is inherited, caused a regression. To fix
that, ensure every project uses its own .rebar/erlcinfo. While at
it, fix the issue that erl_first_files entries were not included
when initializing the dep digraph.

Reported-by: Louis-Philippe Gauthier
Reported-by: Roland Karlsson

Thanks: Tuncer Ayaz