upgrade JUnit version from 3.8.1 to 4.11

Update the JUnit dependency version (in both ANT and Maven) from 3.8.1 to 4.11 and also resolve the obvious warnings for use of deprecated packages and APIs.

Note: this only updates the dependency and makes minimal changes to imports to avoid deprecation warnings, it does not move the existing test cases to the newer JUnit 4 style test process driven via annotations, that is a bigger change for a later time.