* In watch mode, play an audible cue when there is an error.

* Added error-bell option.

* Added error-bell option to documentation.

Both packages have been merged and cross-spawn is now
doing the same as cross-spawn-async before

Currently we build the Sass import graph when the CLI watcher is
started. However the graph is not update updated when files are
added or deleted. The latest is a big deal but the former results
in new files not triggered rebuilds when they're changed. The only
way to currently resolve this is to restart the CLI watcher.

This patch rebuilds the Sass import graph when files are added or
deleted to the watch always works as expected.

Fixes #1538

Renamed parameters to be a little clearer, and marked them public since
they are being exported

For the lazy

The support was added in sass/node-sass#1499

Currently it's a bit of an ordeal trying to get the atomic puush
required for AppVeyor to register a commit on the release branch
and also a tag. Looks like AppVeyor expects you to do release from
the master branch.

Inspired by @nschonni work in #1518 in an attempt to work around
this issue this PR instructs AppVeyor to ignore tags on non-release
branches.

Fingers crossed this makes like easier.

Closes #1518

Closes #1486

Node 6.x has trouble including modules
from MS-DOS drives created with subst.exe.

Since we use use subst only to set
symbols paths in the PDB file, let's
revert to the C: drive when doing tests.

Workaround for: https://github.com/nodejs/node/issues/6500

Previous we manually installed NVM and did the version switching
ourselves. This was required because Trvais didn't support NVM
on OSX builds. This has since [been fixed][1] so lets see how it
goes.

[1:][https://github.com/travis-ci/travis-ci/issues/2311]

This was previously attempted in #1413. Shortly after it's
release proxy users started experiencing installation issues so
this was reverted. It was later determined that #1458 was likely
at fault for the proxy issues.

Full credit for this patch goes to @delitescere.

I've also taken the liberty of cleaning the request config generation.

Fixes #1333

This was partially addressed by bumping NAN in #1496.

https://github.com/nodejs/node/issues/6216
https://codereview.chromium.org/1839983002/patch/1/10002

Fixes #1484

This removes the deprecation warning in Node 6

The human friendly name for an unknown platform, arch or runtime
is currently `false`. With this patch the user is better informed
as to why their environment is unsupported. The raw value is also
output to ease with bug reports.

Closes #1487

v3.6.0: Bump LibSass to 3.3.6

This reverts commit c2d24c23.

Unfortunately got does not have good [proxy support][1] which
was missed during review.

Fixes #1458

[1]: https://github.com/sindresorhus/got/issues/79

This reverts commit 5e21f475.

The solution implemented was not equivalent and resulted in issues
for users with proxies.

Fixes #1458

Fix script/build.js logic

Also, do not add additional spaces.

v3.5.0

Log the error when there is a problem with the binary

This is a messy first cut. We can revisit this in upcomming patches.
The value this will bring to debugging installation errors makes
this worth considered we're about to release a LibSass bump.

Fixes #1161

Bump LibSass 3.3.5

Fix a regression in binary verification

A regression introduced in 22c560c7 broke binary verification
causing the binary to always be built locally.

Fixes #1434

Ouptut a deprecation warning to stdout when using process.sass