#447 Convert OmegaT.vpp to a freely useable format.

[Jean-Christophe Helary]

Convert OmegaT.vpp to an UML format that can be used in free software tools.

Cf. https://github.com/omegat-org/omegat/pull/1462

https://github.com/omegat-org/omegat/pull/1462/files#diff-7be2970e933efca2669c05fe021bd365e71c3eae6c7530e0e07002bfb4e8cd3e