Legacy META commands

[Orion Pobursky]

I'd like to amend the File Format regarding META commands used pretty much only by the original LDraw.exe.

Proposal:
Add the following paragraph after the first paragraph (Beginning "Meta commands (or meta statements...") in the "META Command" section:

The META commands WRITE, PRINT, CLEAR, PAUSE, and SAVE are documented here for legacy purposes only and implementation in new LDraw compliant programs is optional.