Added opencv_testing.sh.in file;
opencv_testing.sh installation guarded by OS check.
(cherry picked from commit d9dc5ffa918639e5d8be76644aef4385def13688)
Env setup for testing package implemented using /etc/profile.d;
Variable with path for all native samples added;
Path for test binaries and test data updated.
(cherry picked from commit 39201e68e2649955f40936a1d07f2d1c64c560f5)