fixed bug in ocl::equalizeHist
Fixed a Wmissing-declarations warning when compiling with MinGW.
Merge pull request #1679 from ilya-lavrenov:ocl_equalizeHist
Merge pull request #1643 from alalek:cmake_fix_java_link_rules
Merge pull request #1682 from SpecLad:Wmissing-declarations
Merge pull request #1683 from alalek:ocl_restore_showdiff
ocl: rewrite boxFilter