Release 2.7.4

New features:
- improved LilyPond support : added export in lilypond-2.4.2 format
- added Slovenian translation, thanks to Matevz Jekovec

Patches included (Matevz Jekovec):
- 000255 added \version "2.0", so convert-ly now works out of the box
         moved \voiceOne,\voiceTwo etc. to the separate lines
  fixed a small typo (LilyPoint -> LilyPond)

Bugs fixed:
- 002487 noteedit doesn't consider ties on MusicXML import
- 002528 triplets unfunctional
- 002532 multirests with one bar
- 002580 small type in INSTALL.de
- 002581 rest symbol printed twice
- 002807 rests should have fermatas as well
- 002809 measure numbers for other voices not printed in .ly file
- 003249 2.7.4 beta crash on RH7.2
- 003296 crash when ALSA synth not running
