JDBC drivers: fix 'Unsupported URL' – drivers might be called witrh wrong URLs and then they should (according to the JavaDoc) return null instead of throwing an exception.
This problem occurred when --test-connection was testing multiple connections in parallel.

 # This code depends on make tool being used

 DEPFILES=$(wildcard $(addsuffix .d, ${OBJECTFILES} ${TESTOBJECTFILES}))

 ifneq (${DEPFILES},)

 include ${DEPFILES}

 endif