OSX java version issues #4

The unit tests are failing because the java.util.Objects class cannot be found at runtime (https://docs.oracle.com/javase/7/docs/api/java/util/Objects.html). java.util.Objects was added in java version 1.7, and should be missing from version 1.6.

FAIL: /proxy/python/tests/test_serialization
FAIL: /proxy/java/tests/test_reflect
FAIL: /proxy/java/tests/test_primitive
FAIL: /proxy/java/tests/test_fields
FAIL: /proxy/java/tests/test_serialization

PothosUtil --self-test1 /proxy/java/tests/test_primitive
Testing /proxy/java/tests/test_primitive...
FAIL!
Exception: Pothos::Testing TestJava.cpp:172 -- Unexpected error after last
checkpoint; Error: Exception: Java::FindClass(java/util/Objects)

It seems as though version 1.6 is the default for OSX, but even after going through the trouble to upgrade the JDK, the error persists. I think this is just a java configuration issue on a system with multiple versions, and many forums seem to concur that this is a known difficulty for users.

We should figure out if this is a real bug or just a configuration issue -- and if so, provide configuration instructions.