added opencv as the optional dependency and a basic test in tests/integration/opencv.
added flags for opencv integration in CMakeLists.txt.
shortened the flag name for OpenCV integration
opencv integration test cleaned_.
removed system include for OpenCV from CMakeLists.txt
cleaned whitespaces.
Merge pull request #2221 from kislayabhi/develop

added opencv as the optional dependency.
Relaxing function check in valgrind suppression file: libhdf5 changed function names.
Merge pull request #2227 from tklein23/develop

Relaxing function check in valgrind suppression file for libhdf5
Forgot to delete RefCount object when done.
Merge pull request #2228 from tklein23/fix_refcount_unittest_leak

Forgot to delete RefCount object (in unittest) when done