OSMF SVN

PARB changes: renaming 'gateway' property to 'container', and renaming 'GatewayChangeEvent', to 'ContainerChangeEvent'.

PARB changes: making "gateway" on MediaElement read-only.

Removing obsolete import.

Change release version to lowercase, per Flex team's request.

These classes weren't tagged at all, updated tagging including the new OSMF 4.0 tag

@productversion OSMF 4.0

1) Modified a integration tests to correspond with the change to PluginInfo becoming a class.
2) Modified the DFXPParser class in the CaptioningPlugin to use the new TimeUtil class in the framework.

Adding new TimeUtil to .flexLibProperties

Adding a new TimeUtil class and corresponding unit tests.

Updated build script with build number placeholder, release version requested by Flex.