This functionality no longer makes sense inside Moodle now that we have
external tools like stylelint to help us with this. It was not able to
be used by any core themes.
The code was always marked as not for external use.
Invalid CSS with extra } symbols, which previously (by fluke)
worked, was broken by recent chunking improvements. This change
makes the chunking code robust against this (stupid) situation.
This commit makes the following changes:
* Tidies up coding style.
* Tidies up phpdocs.
* Improve CSS optimiser unit tests to cover browser hacks.
* Improve backgound style consolidation.
* Improve border style consolidation.
* Fixed optimiser to handle browser hacks like *zoom.
* Improved @ rule unit tests.
* Fixed @rule breakages caused by OS specific rules.
* Added more unit tests to cover a bit more CSS3.
I am pretty sure this patch will now enable to optimsier to
work on bootstrap based themes should developers not wish
to compress thier compiled less CSS.
