v1.5

• MPU port emulation if BLASTER variable contains P=xxx.
• cmdline option /P added.
• cmdline option /SD added.
• fix: volume for SB Live/Audigy wasn't set correctly.
• trap PIC port to reject attempts to mask the real sound hw interrupt
  (Rational DOS extender).
• switch to client context for SB interrupt emulation.
• HDA: improved error msg if card init fails.
• IRQ 2 accepted.
• fix: SFX noise in tyrian2k, also may be in other games that use
  non-autoinit DSP cmds.