SCP: Added debugging support for EXPECT and SEND activities. Fixed SEND buffer queuing bug.
SCP: Add RegEx support to EXPECT string processing
MicroVAX2, MicroVAX1: Updated build configuration to link against the newly updated SDL 2.0.3 code in the  windows-build package.  Fixes issue #93
SCP: Extended EXPECT and SEND to have more flexible activation delays

- EXPECT will now tolerate a HALTAFTER=n parameter which delay the simulator stopping execution for n instructions.  Unpredictable behavior will happen if multiple EXPECT conditions see matching data before the first actualy halt occurs.
- SEND has an AFTER=n argument which delays the initial stuffed data from being input for at least n instructions.  It also has a DELAY=m argument which specifies the minimum number of instructions which must execute between stuffed input data.
- Changed run_cmd() to no longer clear pending breakpoint actions before starting instruction execution.
- Added a -Q switch to the commands which dispatch through run_cmd() (RUN, STEP, NEXT, GO, BOOT, etc.).  This switch will suppress status output when execution stops.  This will allow sequences of breakpoint action commands to silently execute when needed.
VisualStudioProjects: Revised build dependency checking logic to check for the updated SDL 2.0.3 version in the windows-build components.