Support Regular Expressions and Arrays in cssImportIgnore

[sathomas]

CSS file URLs may legitimately include commas. The recommended CSS for Google Web Fonts, for example, might look like:

@import url('//fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,400,300,600,700&subset=latin,cyrillic-ext,latin-ext,greek-ext');

This PR allows cssImportIgnore to support regular expressions and an array of strings or regular expressions in addition to the current format of a single "comma separated list."

Note: Contributor License Agreement for stephen@sathomas.me is on file.

[jrburke]

I think cssImportIgnore needs an overhaul in general: it should have just accepted an array in the build.js form and command line use should have fallen into the "needArray" conversion done in build.js. However, that is a larger, backwards incompatible change, so going to schedule this for 3.0.

In the meantime though, the import inlining should skip URLs that begin with // as those indicate network URLs, which are not supported in the optimizer. If you do find those are slipping through now, then I would want to do a more targeted fix for that in the 2.x series.

[sathomas]

I wasn't aware that r.js had any special handling for import URLs beginning with // (and I still can't find the logic that does so), but I'm new to the app so please forgive the ignorance. I can confirm that setting

'cssImportIgnore': '//fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,400,300,600,700&subset=latin,cyrillic-ext,latin-ext,greek-ext',

does ignore inlining for the import URL in the example. I thought that was just a quirk of the greedy regex matching algorithm, though.