* Add a FLANN example showing how to search a query image in a dataset
* Clean: remove warning
* Replace dependency to boost::filesystem by calls to core/utils/filesystem
* Wait for escape key to exit
* Add an example of binary descriptors support
* Add program options for saving and loading the flann structure
* Fix warnings on Win64
* Fix warnings on 3.4 branch still relying on C++03
* Add ctor to img_info structure
* Comments modification
* * Demo file of FLANN moved and renamed
* Fix distances type when using binary vectors in the FLANN example
* Rename FLANN example file
* Remove dependency of the flann example to opencv_contrib's SURF.
* Remove mention of FLANN and other descriptors that aimed at giving hint on the other options
* Cleaner program options management
* Make waitKey usage minimal in FLANN example
* Fix the conditions order
* Use cv::Ptr
