minify/compress BP javascript

[DJPaul]

We should minify (or compress in some way) the default theme javascript, as there's quite a lot of it. We can package a uncompressed .dev.js version with the theme for developers to be able to read/load from (use the WordPress SCRIPT_DEBUG constant for this).

[r-a-y]

Great idea, DJPaul!

I was worried about the pre-bundled JS scripts in global.js (#1673) that I didn't think about minifying the whole thing!

I'd say this is more of an enhancement than a defect though.

[johnjamesjacoby]

It should follow suit of how WordPress does it with debug constants.

Same could go for the default theme CSS as well.

I like it.

[djpaul]

(In [3476]) Prepare core js/css for minify. See #1891

[djpaul]

(In [3477]) Minify core js/css. Set SCRIPT_DEBUG to load the dev versions. Fixes #1891