Derby related utility methods for the JUnit tests.
The class assumes the tests are either being run
from the build classes folder or from the standard
jar files (or a subset of the standard jars).
If the tests are being run from the classes then
it is assumed all the functionality is available,
otherwise the functionality will be driven from which
jar files are on the classpath. E.g. if only
db.jar is on the classpath then the hasXXX() methods
will return false except hasEmbedded().