updated Russian translation
MpaDecFilter: more correct output type.
MpaDecFilter: updated creation of output SPDIF type.
Added an empty Romanian translation for future work.
Add Romanian translation.

This commit is based on a first version of the translation by Daniel Alămiță.

Refs: #2050.
Inno Setup: Add Romanian translation for non-custom messages.
Give some more room to the translations when possible.
Update Authors, Changelog and Readme.
Add RARFileSource as internal filter.