If you happen to fetch a zip archive of the git repo and try to build
from that, you may, for example, ask erlc to build src/._rebar.erl.
._* are OS X resource forks and not real .erl files. This may also
happen with network filesystems on OS X. To fix that, limit the
files compiled by rebar to include only those which start with
a letter or a digit.

Conflicts:
	THANKS

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.

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

Make sure that eunit/qc_compile_opts works

Extra commits for #129

Since the introduction of -r/--recursive, deps were not properly added
to the code path when running ct, eunit, etc.

To fix that, pass a flag down to process_dir1 and conditionalize
execution of the command. This moves the decision into process_dir1
where we can decide to invoke preprocess/2 and postprocess/2 but not
execute the command.

Without this fix, you'd have to, for example, invoke 'rebar -r ct
skip_deps=true', if you wanted to run base_dir's ct suites with deps on
the code path (while skipping all non-base_dir ct suites).

So, with this patch applied, if you run
$ rebar ct
deps will be on the code path, and only base_dir's ct suites will be
tested.

If you want to test ct suites in base_dir and sub_dirs, you have to run
$ rebar -r ct skip_deps=true

If you want to test ct suites in all dirs, you have to run
$ rebar -r ct

The fix is not specific to ct and applies to all commands.

To be able to add inttest/code_path_no_recurse/deps, I had to fix
.gitignore. While at it, I've updated and fixed all entries.