Restore support for so_name, port_envs and port_sources

Fix rebar_erlydtl_compiler:erlydtl_opts/1 and rebar:run/2

Fix erlydtl dependency check

Erlydtl compiler

zsh completion: fix typos

Add skip_deps=AppListSeparatedByCommas feature.

I agree it's a bit of a weird thing, but it's a reasonable and safe extension. When time comes to properly overhaul stuff, skip_deps should disappear entirely.

Add zsh completion script

This allows `rebar ct suites=abc` to consider all suites when
you have a rebar setup with multiple sub_dirs.

Previously, rebar halted after it could not find the suite in the
first dir. But the suite might be present in another dir (when
sub_dirs contains multiple dirs).

This commit makes it so instead of halting, it prints a warning and
continues with looking for the suite in the other `sub_dir`s.

Note -- This uses try/catch to cause the test to be skipped because
otherwise I needed to adjust the return values of 4 functions, the
code path is pretty deeply nested here. Otherwise the whole call chain
needed to be adjusted for this return value:

`run_test -> make_cmd -> get_suites -> find_suite_path`

IMHO, I think for exceptional cases like this it is fine to use throw;
specially since only the {skip} is catched and nothing else.

For enable to shell-completion in zsh.

Add support for minimum OTP versions

Revert arch string changes

When a DTL template includes other template files, those files don't need
to be compiled separately, and therefore can be given an extension different
from `source_ext` (such as `.dtli`) to avoid being compiled.  This fix
allows rebar to find included dependencies with names `*.dtl*` rather
than `*.dtl` and properly determine if a template file needs to be recompiled.

Handle the case where the error didn't occur in the file being
compiled.  That is, if there is an error on line 9 of bar.hrl,
instead of:

/path/to/foo.erl:9: type foo() already defined

print:

/path/to/bar.hrl:9: type foo() already defined

The printed message is made more terse.

Example before applying patch:

    ERROR: Compiling template src/view/test.dtl failed:
      {error,{"src/view/test.dtl",
              [{{4,7},
                erlydtl_parser,
                ["syntax error before: ",["\"\\\"HELLO_WORLD\\\"\""]]}]}}

Example after applying patch:

    ERROR: Compiling template "src/cmp_html_error_template.dtl" failed:
        (line:3, col:12): ["syntax error before: ",["trans"]]

Added a backward compartible feature to specify `erlydtl_opts' options
for the DTL template compiler to allow inclusion of templates in different
directories with different compilation settings for each. E.g.:

    {erlydtl_opts, [
          [{doc_root, "src/view"}, {module_ext, "_dtl_vw"}]
        , [{doc_root, "src"},      {module_ext, ""}, {recursive, false}]

        , {out_dir,   "ebin"}
        , {compiler_options, [verbose, debug_info]}
    ]}.

The definition above is identical to this (the last two options
are duplicated in each list):

    {erlydtl_opts, [
          [{doc_root,   "src/view"}
          ,{module_ext, "_dtl_vw"}
          ,{out_dir,    "ebin"}
          ,{compiler_options, [verbose, debug_info]}]

        , [{doc_root,   "src"}
          ,{module_ext, ""}
          ,{out_dir,    "ebin"}
          ,{compiler_options, [verbose, debug_info]}
          ,{recursive, false}]
    ]}.

In this case "src/view" and "src" directories containing template files
will be compiled.  A new `recursive' option tells rebar_erlydtl_compiler
to search files recursively from a given doc_root.  In the example above
the "src" directory won't be scanned recursively, and the target template
name for target beam modules won't have "_dtl_vw" suffix.

Add support for non-Erlang/OTP (raw) dependencies

Fix return value of rebar_overlay

Add hostname variable to reltool overlay templates

When 'rebar overlay' is run rebar_core got a wrong result
{Config, ok} from rebar_reltool instead of {ok, Config}.

Introduce a new 'raw' option for dependency specs in rebar.config file.
For example:

{deps,
    {dependency_name, "1.0.*",
	 {git, "<...>", {branch, "master"}},
	 [raw]
    }
]}.

When this option is specified, rebar does not require the dependency to
have a standard Erlang/OTP layout which assumes presence of either
"src/dependency_name.app.src" or "ebin/dependency_name.app" files.

'raw' dependencies can still contain 'rebar.config' and even can have
the proper OTP directory layout, but they won't be compiled.

Only a subset of rebar commands will be executed on the 'raw'
subdirectories:

	get-deps, update-deps, check-deps, list-deps and delete-deps.

Restore previous 'git describe' behaviour as discussed here:
http://lists.basho.com/pipermail/rebar_lists.basho.com/2012-September/001713.html