Merge branch 'master' into major

Conflicts:
	CHANGES.md
Remove FF2.x and FF3.x leftovers.
Update Gecko version in env.isCompatible.
Remove Opera leftovers.
Remove env.opera.
Remove IE6 & IE7 leftovers.
Update IE version in env.isCompatible.
Remove class cke_browser_ie6.
Remove unnecessary brackets.
Fix wrong changed IE Quirks.
Simplify webkit case.
Removed dialog_ie7.