Update Dependencies for Node v4

[ajmueller]

I've noticed a handful of issues with the latest major release of Node and the dependencies being used. Here's a quick breakdown:

• gulp should be updated to at least 3.9
• gulp-sass should be updated to at least 2.0.4
• gulp-autoprefixer should be updated to at least 3.0.2
• gulp-combine-media-queries is completely broken and should be removed; it hasn't been updated in a very long time
• gulp-minify-css should be updated to at least 1.2.1; it now uses clean-css which includes media query combining, though I've run into issues with it (see #607, on which I commented, and #645).

I'd put this all in a PR, but I just finished catching all of these issues on one client project and need to hop on a call for another.

[elseloop]

Thanks, @ajmueller! I've been wanting to test this and boom! you beat me to it. I'm hoping to get this all taken care of and out by Friday, should you be bored an looking to write up a PR.

[ajmueller]

You just keep knocking it out of the park with these Bill Murray GIFs.

[pc-pdx]

yesyes. i've just grabed a fresh checkout as of yesterday and had to manually copy [ Assets\src\node_modules\gulp-combine-media-queries\node_modules\through2\node_modules\readable-stream ] over from an existing project in order to complete a build. Seems this a known, possible race issue, FWIW.
All that aside, i believe i'm still running node 0.10.33 and as such, this readable-stream issue may be a full-stop blocker (?) - let me know if that warrants a separate ticket as i've found it impossible to build without intervention. tl;dr:

[elseloop]

Fixed in 2.2.0 release