This change makes the memory manager work again for detecting leaks, the built in one kept coming into de-ref and other bugs so this is the start of a refactor to get it working.
This commit deals with the problem that the keyframe timestamps are not standardized. Seconds, milliseconds and ticks are used depending on the import format. There is no metadata or property that specifies the format used, so the option is exposed to the user as part of the import options gui.