`has()` only tests for an argument presence which is always true for
arguments with default values. Use `get<bool>()` to check the value
instead.

Also:
- Silence clang warnings about unsupported command line arguments
- Add diagnostic print to calib3d test
- Fixed perf test relative error check
- Fix iOS build problem

IPP can be switched on and off on runtime;

Optional implementation collector was added (switched off by default in CMake). Gathers data of implementation used in functions and report this info through performance TS;

TS modifications for implementations control;

Now it allows choosing between arbitrary implementation variants.

now DeviceInfo provides full information about device (from cudaDeviceProp)

Use min/max bounds instead of local value to calculate acceptance threshold.
Threshold based on local values somethimes does not work because cancellation
of big values may produce error bigger than local value.