2.5.2

Synths:

• #407 Roland D-50/D-550 finally we can confirm we have a working adaptation for the Roland D-50/D-550. Special thanks to @summersetter for
  relentless and systematic testing!
• #398 Waldorf M - works now! Thanks to @RadekPilich for testing!
• Sequential Trigon-6 confirmed as working!
• #335 #415 Oberheim OB-X8 works now, also detects module and name length fix.