Add getSourceFromBrowser for CSS documents

[sebaslv]

Adds LiveCSSDocument.getSourceFromBrowser() by adding getStylesheetText() to protocol layer to be used as the underlying infrastructure for CSS Editing unit tests. This PR also includes an initial test for CSS Editing.

[redmunds]

The comments make it sound like these blocks are mutually exclusive, so shouldn't this be else if (...) ?

[sebaslv]

Actually yes, I'll change that.

[redmunds]

I'm seeing new unit test fail:

should push changes through browser connection

TypeError: Cannot call method 'replace' of undefined
    at fixSpaces (file:///C:/Users/redmunds/dev/github/brackets-shell/Release/dev/src/extensions/dev/brackets-livedev2/unittests.js:54:24)
    at null.<anonymous> (file:///C:/Users/redmunds/dev/github/brackets-shell/Release/dev/src/extensions/dev/brackets-livedev2/unittests.js:222:28)
    at jasmine.Block.execute (file:///C:/Users/redmunds/dev/github/brackets-shell/Release/dev/test/thirdparty/jasmine-core/jasmine.js:1064:17)
    at jasmine.Queue.next_ (file:///C:/Users/redmunds/dev/github/brackets-shell/Release/dev/test/thirdparty/jasmine-core/jasmine.js:2096:31)
    at onComplete (file:///C:/Users/redmunds/dev/github/brackets-shell/Release/dev/test/thirdparty/jasmine-core/jasmine.js:2092:18)
    at jasmine.WaitsForBlock.execute (file:///C:/Users/redmunds/dev/github/brackets-shell/Release/dev/test/thirdparty/jasmine-core/jasmine.js:2576:5)
    at file:///C:/Users/redmunds/dev/github/brackets-shell/Release/dev/test/thirdparty/jasmine-core/jasmine.js:2590:12

[redmunds]

Done with code review.

[sebaslv]

It seems the failure is related to getStylesheetText not retrieving the code from the browser side. I'm not able to make it fail even running on different browsers (IE, Firefox and Chrome). Which browser are you using to run it?

[redmunds]

I'm on Windows 7 and my default browser (where tests are being run) is Firefox.

[sebaslv]

Added a couple of changes to the implementation of getStylesheetText. Tests are passing in Firefox and Chrome on my environment (Windows 8) against master branch of Brackets. Could you please check them now? Thanks!

[redmunds]

We're trying to finish up Brackets 1.0 this week and next week, so not sure when I'll get to it.

[redmunds]

I'm still seeing same error on Win7/Firefox, which I'm also seeing in pull request #28

[redmunds]

I verified that tests pass on MacOSX 10.8/Safari.