Merge pull request #3 from erendrake/develop

Sync with origin develop
Changes to execution rules for RT2 based on connection status

1) Allow immediate mode queue to wait for re-acquisition of signal, then
continue running.
2) Abort programs running from a volume that goes out of range .
3) Don't allow execution of programs from volumes that may be active,
but have gone out of range since switching to it.
4) Allow execution of programs on local volumes to continue even if
signal is lost.
Merge pull request #53 from jwvanderbeck/RemoteTech_ExecutionStates

Changes to Execution Contexts based on signal