Force English strings in project files.
Add support for MMS streams through LAV Splitter Source.
Internal filters: always try LAV Filters in low merit mode.

This means even formats that aren't listed in the internal filters option page will be loaded by the internal filters if no other filter is available.
Add a command line switch (/device) to open the default video device.

This commit fixes #533.
Remove now unused internal filters strings from resources.