Fix short block writes on RK06/RK07 devices to write zero filled buffer data. (Oleg Safiullin)
Remove unused definitions
Add sim_video and VAX QVSS (VCB01) Monochrome Video Board from Matt Burke
Fix incorrect definition descriptions in comments
Added logic to suggest libSDL might help with simulators what can use it when it isn't available.
Fixed reporting of libSDL availability in simulatoes which will never need it.
Added reporting of the QVSS window focus release key when Video Windows is created
Cleanup Visual Studio Build issues
Fixed the Visual Studio build of simulators which statically link against libSDL.
Add descriptions to the QVSS register declarations
Added "HELP SET dev" and "HELP SHOW dev" as eqivalent to "HELP dev SET" and "HELP dev SHOW" respectively.
Renamed Visual Studio Projects VAX610, VAX620 and VAX630 to be consistent with the target names produced by those project builds.

This allows the projects to be migrated into Visual Studio 2010 and Visual Studio 2012 and produce consistent behavior.
Cleanup of Visual Studio VAX project to properly convert to newer Visual Studio versions.
Update README
Merge remote-tracking branch 'github.com/simh/simh/master'