VxWorks 6.x can make environment variables private to each
thread, which doesn't work too well.
A test failure on VxWorks explains how to change the image
configuration to fix this.
its own unit test program in libCom/test; changed ellFree() to take a
function pointer for the free() routine, so it can be used on Windows;
modified epicsExit and dbBkpt to use it and pass in the free routine.
Removed all Main.cpp files, use the macro in testMain.h instead and
defaulted all argc/argv parameters.
Converted all real test programs to use epicsUnitTest.h.
Moved performance measurements from epicsThreadTest to epicsThreadPerform.
Moved epicsOkToBlockTest tests into epicsThreadTest.
On a host arch, make test inside the O.arch directory runs all tests.
Michael Davidsaver