PDP-11, VAX: Expand DTYPE mask size, fix RF35, add new devices to RQ sim

The disk type mask width (UNIT_W_DTYPE) was increased to six (6) bits, doubling
the possible number of disk types definable to sixty-four (64).
The RF35 was not entered in either the drv_tab or drv_types tables, causing any
set command issued for the drive type defined after the RF35 -- the RF71 through
RF73, as well as any disk defined after the RF73 -- to act incorrectly.
The ESE20 solid state disk and ESE50 series of solid state disks are
added based on simple drive geometry and size information without any parameters
for bad block management (not that it is used in the simulation anyways). The
ESE50 series drives are labelled as they are in the MSCP specification document,
the Ultrix-32 v4.5 disktab, and the Media Type noted in the "ESE50 SDI Solid
State Disk User Guide" (EK-ESE50-UG.B01):
 * ESE50-A: ESE52
 * ESE50-B: ESE56
 * ESE50-D: ESE58
The RD33 is added based on the geometry of the Microscience HH-1090 hard disk
drive, with the bad block management information calculated from the bad block
information for the other RDxx series drives.
The RX18 is added based on the geometry of the RX180 floppies in the VT-180
"Robin" CP/M system, which are noted in the MSCP specification document as a
possible device. Specific information is taken from the "VT-180 Series Technical
Manual" (EK-VT18X-TM-001).