Replace all "float" by "double" (64-bit) to avoid "lose precision"
warnings.

Fixed integer vs unsigned integer comparison in .cpp test source and
trailing whitespaces in source code

As the opencv's build-bot did not want to compile this revision, I had
to do some changes. In particular,
1) Removed unsigned int vs int comparisons, that were treated as errors
2) Removed unused variables and functions
3) Removed functions without previous declaration
4) Fixed whitespaces

This is an implementation of primal-dual algorithm, based on the C++
source code by Vadim Pisarevsky. It was extended to handle the denoising
based on multiple observations. It also contains documentation and
tests.

it conflicts with cv::detail

changed default parameters in CreateERFiltersNM{1,2} functions. They are not needed now in the sample example.

This allows to get rid of the last remaining Ptr<T>::addref calls.

Also changed the static functions to inline, to stop GCC complaining
about unused functions.

Now the features2d class wrappers use composition instead of inheritance.