Allow passing a few useful arguments to node-sass binary

Learn logic

Specifically, a `cwd` and `output_style` so partials can be loaded correctly and we can compress out output

Node v0.10.0

Response to Issue 65

Changed the default file name for generated CSS files from nodesass.css
to <originalfilename-without-scss>.css.

Now it should be possible to use globbing and get all generated files in
ones current working directory:

./path/to/node-sass path/to/styles/*.scss

generates all CSS files named like their SCSS counterparts.

Canon libsass

Use a wrapper to store the callback info and the context, this way we
can use the unmodified libsass

Convert the options to camelCase. Fixes #43

Still supporting the old style though

Pull request looks okay.  I'm merging it in.

re #61 proper linux x64 binaries

Just a simple bugfix at npm install line in readme file

Conflicts:
	README.md