INT 15 - DESQview v2.40+ - "GETDVPATH" - GET DESQview DIRECTORY
        AX = DE25h
        ES:DI -> 67-byte buffer for ASCIZ directory name
Return: ES:DI buffer filled with directory from which DESQview was started
BUG:    DV 2.42 does not place a terminating NUL at the end of the directory
          name, so if the buffer is not cleared to zeros before the call,
          there is no way to tell where the directory name ends.  This bug
          has been fixed in DV 2.52 (DV/X 1.02)
SeeAlso: INT 21/AH=47h