When running 'rebar qc' or 'rebar eunit', we were erroneously fetching
erl_opts more than once.

test_compile/3 is used by eunit and qc, but the comment was only
referring to 'rebar eunit'.

CWD plugins regression

Speed up the compilation process v5

* 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

* Do not parse source files twice while checking for relationship.
* Keep files relationships in a graph.
* The option 'keep_build_info' is introduced. When set to 'true'
  the graph will be kept in ebin/.rebar.build.info and will be
  used by further compiler calls. The default is 'false'.

docs: fix #228

eunit: fix dialyzer warnings introduced in 03da5e0b

Document support for abbreviated commands

Adapt erlydtl compiler plugin to latest version of erlydtl

Add random_suite_order option to eunit command

Option takes either 'true' or a numeric seed value. If true is passed, a
random seed is generated and used. The numeric seed value is for
repeatability.

The idea here is to root out test suites that are order dependant, or
that fail in the presence of certain orderings.

allow suite[s] or test[s] as options for eunit and ct

Xref extra path

Added R16B01 and R16B02 to travis config.

Fix basho/rebar#388

Remove experimental flags

Document compile_only=true

Fix #205 (erlydtl:compile/3 returns warnings)

If the syntax error is in a .hrl file, then the reported error message
is not as useful because it's not clear which .erl file was being
compiled. We can fix that easily by first printing what source file was
being processed. We don't change the actual error message, so this will
still work with your editor of choice for jumping to the right line.

Before
------

Success:
Compiled src/foo.erl

Failure:
include/foo.hrl:10: syntax error [...]

After
-----

Success:
Compiled src/foo.erl

Failure:
Compiling src/foo.erl failed:
include/foo.hrl:10: syntax error [...]

Fix #187 (rename getopt and mustache)

Print a more appropriate message on 'rebar info'

generate-upgrade can now take target_dir argument

erlydtl implemented 'binary' option. Add new clause for {binary, false}.

Remove experimental flag from:
* qc compile_only=true
* eunit compile_only=true
* src/foo.app.src.script
* eunit tests=

Adapt rebar_erlydtl_compiler to handle warnings emitted by
erlydtl:compile/3.

While at it, update getopt.erl to git rev 78eda3b.

To avoid treating plugins' info/2 functions as commands, we catch calls
to 'rebar info'. Previously (4b8c81fb) we simply printed the help
string, but it's much more informative to print the following:
Command 'info' not understood or not applicable

inttest/rgen_1: double the timeout a second time

Clean up rebar.config.script