KS10 UBA fixes; CR11/CD11/CD20 overhaul, tmxr bugfix

This update will synch my non-kdp code to the project.

The KS10 UBA was not correctly handing merges.  The quick fix that Rob put in a while ago was incomplete.  Also, the UBA needed a standard mechanism for 18-bit transfers.

tmxr could create a nasty cycle of errors when it overloads and sends a text error string on a ;notelnet connection.

The CR11/CD11/CD20 was completely broken for TOPS-10/20.  There was no emulation of augmented image mode, and timing of error bits was causing phantom cards to appear regularly.  This edit may not be the final solution, but it passes my test cases on 36-bits, builds and the cli works on 16 and 32 bits and is a step forward.  I don't believe I broke the CR11 emulation, but it needs re-testing.  It's possible that it doesn't have all the fixes, but it shouldn't be worse than before.  There may be more to do based on additional testing, but it's time to establish a new baseline.

Testing by folks who have 16 and/or 32-bit system disks setup would be appreciated.