Build errors: Include guard missing from epicsUnitTest.h;
dbShutdownTest.c was calling the non-universal strcasecmp()
instead of epicsStrCaseCmp().
ioc/db/test no longer depends on std. I modified
xRecord to make it a working record type, and simplified the
other test programs so they all use the same new expanded
dbd file rather than each making their own. I also added
dbShutdownTest() to epicsRunDbTests().
