Create Url.as

Relative to absolute path.
Update HTTPStreamingHLSIndexHandler.as

Relative to absolute path stuff moved to org.denivip.osmf.utility.Url
Merge pull request #1 from Alekscs/patch-3

Relative to absolute path and slash issue - updated and moved to new class
Merge pull request #64 from Alekscs/patch-2

Relative to absolute path and slash issue - updated and moved to new class