Merge pull request #77 from Halopend/temp

Remove individual X,Y,Z homing from delta printers
Adde missing OPSMoveAfter initalization, added board 21 gen3 PLUS
Compilation bugfix for I2C beeper

Software does not compile when you define a beeper connect through I2C.
Merge pull request #80 from Jerome-PS/patch-1

Compilation bugfix for I2C beeper
Added Melzi board, bug fixes
Implement M300: Play beep sound
Merge pull request #84 from DDRBoxman/master

Implement M300: Play beep sound
Set min. start speed based on acceleration, italian translation
Removed debug output
Merge branch 'master' of https://github.com/repetier/Repetier-Firmware