TMXR: Added support to reasonably set modem bits when a line has dedicated listen port defined or uses datagram transport.
SCP: Add SHOW -C BREAK to display the currently defined breakpoints as commands which can be used to redefine them later.

Note: This excludes the possibility of there being a -C breakpoint type.  Since there are potentially 26 different breakpoint types, this exclusion is not likely to have a significant impact.
VAX,PDP11,PDP10: Added explicit support to enable (or disable) DMR Micro Diagnostics which corresponds to the SW10 hardware switch.

Also, always process initialization commands without regard to whether the DMC/DMR line is attached and return diag error status if the line isn't attached.