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.

- 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.

attempt to emulate the behavior of
`erl -pa ebin -pa deps/*/ebin`

fix error messages and formatting issues of `rebar shell` by
shutting down and restarting the user subsystem in a mode more
hospitable to the shell than the simple user started when run
as an escript. emulate `error_logger` behaviour when the shell
is run via `erl`

add documentation of the shell command

limitations:

the erlang interrupt handler is not enabled when running as an
escript and there is no interface to re-enable it via erlang code.
this means `ctrl-c` will immediately exit the running process
unlike when running the shell via `erl`. `ctrl-g` is, however,
unaffected

the user subsystem is killed and restarted but not supervised. if
your code somehow relies on the user subsystem crashing and
restarting `rebar shell` may interfere with it's operation

Add my name to THANKS

* update files
* fix Dialyzer warning
* unconditionally enable info fil
* clean-up inconsistencies
* use term_to_binary compression
* use try...catch instead of case...catch...of
* do not write build info file if the graph is unmodified
* store info file as <base_dir>/.rebarinfo
* properly support list of compile directives
* fix regressions:
 - Fix a bug in handling of files to compile first.
 - If a file that is depended upon itself depends on other files, make sure
   those are compiled first. While at it, rename variables for correctness.
   Reported-by: David Robakowski
 - Make sure that FirstFiles has no dupes and preserves the proper order.
 - headers referenced via -include_lib() were not properly resolved to absolute
   filenames
 - .erl files found in sub dirs of src_dirs were not properly resolved to
   absolute filenames