PKG_INTD, Deregister interrupt handler

rst $08, defw $1a0f


IN:	A=reason code;
		int_prc, deregister single process interrupt routine
		int_pkg, deregister global package interrupt call
	HL=package call ID that was previously registered (if A=int_pkg)
OUT(success):
	Fc=0
OUT(failure):
	Fc=1
	A=rc_hand, no installed handler found
	A=rc_unk, unknown reason code

Registers changed after return:
  ......../IXIY same
  AFBCDEHL/.... different

Notes:
	Applications *must* always deregister any process interrupt before
	terminating
