Figure out how to handle time-stamps on freeze & resume

[forderud]

Extension of #22.

Alternative approaches:

• [ ] Per-frame CreationTime editing: Works fine with StreamReceiver, but Google Chrome pauses video playback if the time-stamps increase too slowly, and playback doesn't resume automatically
• [ ] #32 Transmit a new "tkhd" or "mdhd" atom with new CreationTime when resuming a scan
• [ ] ~~Add Supplemental Enhancement Information (SEI) message that supports arbitrary byte arrays.~~ (not needed for high precision timestamps)

It's already been proven that custom SEI messages can be used to add additional frame time-stamps, that can be freeze & resume while the video is playing.

Other links

• MPEG supplemental enhancement information (SEI) (stored in "moof" atom, "mdat" box)