Avoid passing more than one instance of ERL_LIBS to child processes

This commit fixes issue #98 by removing the ERL_LIBS and REBAR_DEPS_DIR
from the list of environment variables exported by the rebar_port_compiler
plugin.
Incorrect REMSH args when sname is used

When a node is configured with -sname in app.config or sys.config the
REMSH_NAME_ARG and REMSH_REMSH_ARG arguments are incorrect due the
assumption that the node name always contains '@'.

To fix the bug, the script tries to find '@' and then compose the
arguments acording to node name type. If in long name mode the
script can't compose a correct node name exits with warning.
Make REMSH node run in hidden mode

To avoid problems with REMSH node being visible from another nodes
starts it in hidden mode (erl -hidden).
Allow specification of module dependencies for appups

The order in which modules, within an application, are loaded can be
important. This patch adds allows the specification of module
dependencies such that generate .appup/.relup scripts will load a
module's dependent modules before itself.

To use:

in rebar.config, add a module_deps

{module_deps, [{ModuleName, [DependentModuleName, ...]}]}.

ModuleName is the name of any module, followed by a list of module
names that it depends on.
Add test for regression caused by 252b31f (#90)
rebar_core: minor comment fix
Fix regression caused by 252b31f (#90)
inttest/depplugins: update docs
introduce xref_extra_paths
Added R16B01 and R16B02 to travis config.
allow suite[s] or test[s] as options for eunit and ct
Bump rebar to 2.2.0 and add proper release notes
Merge pull request #219 from h4cc/patch-1

Added R16B01 and R16B02 to travis config.
Merge pull request #188 from massemanet/xref_extra_path

Xref extra path
Merge pull request #224 from andrewjstone/allow-test

allow suite[s] or test[s] as options for eunit and ct
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.
Add documentation
Merge pull request #223 from rebar/adt-random-suite-order

Add random_suite_order option to eunit command
Adapt erlydtl compiler plugin to latest version of erlydtl
Use proplists:unfold to make sure we feed a proplist to keymerge.