save the planet - reduce size of HLSProviderOSMF.swf from 147 kB to 83kB

after reviewing link-report.xml, we can see that LoadDocumentFromElement is introducing lots of dependencies (XMLLoader, f4f, and plenty of other stuff)
create a new class HLSLoadFromDocumentElement.as in HLSProvider, inspired from LoadDocumentFromElement.as but without the dependency to XMLLoader
=> this saves around 64KB