Clean up throttle tests
Check false positives when testing the value of `this`
Fix issue #472

This commit fixes #472 by replacing cssreset/cssfonts
dependency with cssnormalize.
Update request module and node engine requirements
Remove path.existsSync as part of node 0.8 minimum environment
Update IO history
Update core history
Merge pull request #913 from juandopazo/throttle-tests

Clean up throttle tests
Merge pull request #924 from tilomitra/cssgrids-dependency

Fix issue #472
Build YUI for merge of #924
Merge branch 'request-update' of git://github.com/clarle/yui3 into dev-master