IOC Test Framework: Launch without running tests

[DominicOram]

As a developer I would like to run up an IOC and emulator quickly and easily for a variety of reasons. Currently I can do this by:

• Run Lewis from command line then the IOC with correct macros (This is a faff)
• Create a dummy test in the IOCTestFramework that just sleeps for a while (Means commenting out all other tests and I can forget I put it in there)

It would be good if the IocTestFramework had a no-tests flag where it would boot up my emulator and connect an IOC to it and just run in that state indefinitely.

[RaiBishal]

@John-Holt-Tessella says he has started this in his current ticket

[John-Holt-Tessella]

ISISComputingGroup/EPICS-IOC_Test_Framework#238