os/2 table doesn't check for version

[Pomax]

https://github.com/bramstein/opentype/blob/master/src/tables/os2.js#L58 may cause interesting problems, as versions for OS/2 tables version 0, 1, and 2 contain fewer records.

• version 0 table ends after usWinDescent
• version 1 table ends after ulCodePageRange2
• version 2 table ends after usMaxContext

It might also be worth adding a check based on the SFNT table directory length; if you're reading more data than the directory "length" value says there should be, something potentially bad is going on.

[bramstein]

Thanks for letting me know! I've corrected the OS/2 table parser and released a new version. I've been meaning to write some test suite for this library that simulates input for all versions and checks it is parsed correctly. I'm extremely busy at the moment but I hope to get to it soon.