Rename mplayer.*.{rc,po(t)} to mpc-hc.*.{rc,po(t)}.

Also use more appropriate language codes for the language DLLs.
PPageShaders: remove refactoring leftover

CID 1135355
Reposition toolbars properly on media close
Clear osd messages in CloseMedia()
Option to delay playback after mode auto-switch

Fixes #3235
Make use of mouse nav buttons in Playlist panel
Translation script: Fix the PO header getting mixed line endings.
Add the config file for the Transifex client.
Updated Basque translation.
Update German translation.
Updated British English translation
Updated French translation.
Updated Simplified Chinese translation.
Updated Polish translation.
Drop unused code from the old internal filters era.