Support output_handler = ob_gzhandler in script/style compresser

[DD32]

My host setup uses output_handler = ob_gzhandler in order to allow for non-compressed output (Which isnt possible with zlib) for certain scripts, Under the current trunk, In the event that this setup is used, WordPress becomes unable to load the Styles (and quite possibly scripts).

Whilst theres a test in the JS loader, i'm not sure how its working.. since i was getting a non-styled page under IE/FF.. (Opera handles double gzip encoding fine..)

The attached patch adds a test for the above case to the load files.

[azaozz]

(In [10466]) Support output_handler = ob_gzhandler in script/style compressor, props DD32, fixes #9000