OmeroCpp: Disable RMap and search tests

Note: CmdCallbackTest.testDoAllTimingFinishesOnLoop is also buggy, possibly with timing problems.  It fails consistently for me from home over a broadband connection:

```
[----------] 7 tests from CmdCallbackTest
[ RUN      ] CmdCallbackTest.testTimingFinishesOnLatch
[       OK ] CmdCallbackTest.testTimingFinishesOnLatch (4964 ms)
[ RUN      ] CmdCallbackTest.testTimingFinishesOnBlock
[       OK ] CmdCallbackTest.testTimingFinishesOnBlock (4939 ms)
[ RUN      ] CmdCallbackTest.testTimingFinishesOnLoop
[       OK ] CmdCallbackTest.testTimingFinishesOnLoop (5105 ms)
[ RUN      ] CmdCallbackTest.testDoNothingFinishesOnLatch
[       OK ] CmdCallbackTest.testDoNothingFinishesOnLatch (4782 ms)
[ RUN      ] CmdCallbackTest.testDoNothingFinishesOnLoop
[       OK ] CmdCallbackTest.testDoNothingFinishesOnLoop (4319 ms)
[ RUN      ] CmdCallbackTest.testDoAllTimingFinishesOnLoop
/Users/rleigh/code/ome/components/tools/OmeroCpp/test/integration/cmdcallbacktest.cpp:75: Failure
Expected: (steps) >= (1), actual: 0 vs 1
[  FAILED  ] CmdCallbackTest.testDoAllTimingFinishesOnLoop (4384 ms)
[ RUN      ] CmdCallbackTest.testAddAfterFinish
[       OK ] CmdCallbackTest.testAddAfterFinish (5533 ms)
[----------] 7 tests from CmdCallbackTest (34026 ms total)
```

--no-rebase

--------

Testing: http://ci.openmicroscopy.org/view/Failing/job/OMERO-5.1-breaking-cpp/ should go green.