Use readyState to trigger removal of old <link> [#198]

Previously we had a fixed 200ms delay before removing the old
stylesheet on live CSS refresh.  I'm not sure why it has been done
that way.  Problem is that Sprockets asset pipeline often takes more
time to produce a CSS file, causing a flash of unstyled content for
Rails developers.

Waiting until readyState is 'complete' is clearly a superior way to
detect when the new stylesheet has finished loading, and that's what
this commit implements.

Tested in Safari, Chrome, Firefox and Opera, and seems that it should
work in IE too.
Version bump to 2.0.8
Use unload+polling to trigger removal of old <link> [#198]

Previously we had a fixed 200ms delay before removing the old
stylesheet on live CSS refresh.  Problem is that Sprockets asset
pipeline often takes more time to produce a CSS file, causing a flash
of unstyled content for Rails developers.

Most browsers have recently started to support onload event for CSS,
so it makes sense to switch to that, plus polling every 50 ms.

Tested in Safari, Chrome, Firefox and Opera. (Current stable Safari is
the only major browser that uses polling; Safari 5.2 on 10.8 should
support onload too.)
Fix live CSS refresh to work with prefixfree [#185]

Prefixfree replaces original <link> with a <style> element, so we need
to add some special handling for it:

- match style[data-href] against incoming CSS paths

- properly create a replacement <link> when the original is a <style>

- invoke PrefixFree to re-process the updated CSS

StyleFix is a name of a framework that PrefixFree is based on.
Update livereload.js
Merge branch 'master' of git://github.com/livereload/livereload-js