Bump Libsass and sass-spec to 3.2.0

Set User-Agent: HTTP header

Introduce SASS_BINARY_SITE environment and refactor API tests

Pin to nan@^1.8.4

Separate testing of all configuration
and runtime paramenters into a separate file.

Reduce bolierplate code and
use startup/teardown to restore
test context.

Implement additional single-parameter
tests for configuration variable.

Provide ability to locally mirror node-sass
binaries for various versions and platforms.

SASS_BINARY_SITE needs to be an URL pointing to
a collection of files organized like the Github
repository.

If SASS_BINARY_SITE is set to

 http://myhost:8080/local/node-sass-bin/

then

 http://myhost:8080/local/node-sass-bin/v3.0.0-beta.5/freebsd-x64-14_binding.node

should point to the FreeBSD 64 bit binary for node 0.12.0

The URL can be also specified as the --sass-binary-site
commandline option or in the package.json:

 "nodeSassConfig": {
   "binarySite": <url>
 }

Remove --sass-binary-url and friends.

Also change priority and use package.json defaults
last, after command line arguments and the environment.

Show expected binary path in the error message if bindings not found

Kill watcher processes during test

After running npm test four node processes
keep on running:

85880  1  S        0:00,41 node node-sass/bin/node-sass --watch node-sass/test/fixtures/simple/tmp.scss
85883  1  S        0:00,41 node node-sass/bin/node-sass --watch --quiet node-sass/test/fixtures/simple/tmp.scss
85885  1  S        0:00,40 node node-sass/bin/node-sass --output-style compressed --watch node-sass/test/fixtures/simple/bar.scss
85888  1  S        0:00,42 node node-sass/bin/node-sass --output-style compressed --watch node-sass/test/fixtures/watching/index.scss

We need to explicitly kill them when the test is done.

This release was created to hotfix an npm release issue.

Release 3.0.0 beta.6

Update sourcemap test to match updates in Libsass

Clarify custom importers and functions are still experimental

Handle build script git operations in JS

Fix bug with join defaulting to comma separator

Init libSass submodule when npm installing via git url

CLI: Adds --quiet flag

Close #713 (handle->flags & UV_CLOSING) assertion failure

Admin: Promoting Michael Mifsud to project lead

It is not safe to delete uv_async_t object after
calling uv_close(). This object remains in the
closing queue and can be purged only in the final
callback.

Fix typo lenth->length

Addresses #697.

Fixed lint error which was causing tests to fail.