Don't rely on isTTY for stdin/stdout

Misc. Fixes

Also updated sass-specs.

Actually isTTY is only relevant if we want to see whether we really have to read from stdin.

If isTTY is falsey (i.e. empty), the cli will attempt to read from stdin even if it is passed an input filename.

As assert aborts the code execution if the file exists, this test will result in the file not being deleted if it exists. This change makes sure the file is cleaned up if it exists, before the assert has a chance to abort.

Tweak CLI output indentation

Test: SourceMap in stats with renderSync

Stats: Passes updated sourceMap to finishStats()

* jasonsanjose-brackets-sass-readme:
  Alphabetize list
  Add link to Brackets
  Add brackets-sass to list of usages

Merge branch 'brackets-sass-readme' of https://github.com/jasonsanjose/node-sass into jasonsanjose-brackets-sass-readme

* 'brackets-sass-readme' of https://github.com/jasonsanjose/node-sass:
  Alphabetize list
  Add link to Brackets
  Add brackets-sass to list of usages

Conflicts:
	README.md

Fixes #472.

Use meow instead of yargs

Removed node-sass-middleware as a dependency

Code: Updates libsass to v3.0 and sass-specs

Update test runner to match sass-spec

- The sass-spec runner by default looks for `input.json` and will skip
  any test which doesn't have one. Mirror that behaviour by skipping the
  test run if an `input.json` file doesn't exist.
- The sass-spec folders have been moved around so update the ignored
  folders to match where the todo tests now live.

Code: Updated to latest master and fixed a test

Added some more keywords to package.json