Makefile: split compilation and linkage

This fixes an error when compiling with clang++:

  clang: error: cannot specify -o when generating multiple output files
  <builtin>: recipe for target 'opencv_trail_effect' failed
  make: *** [opencv_trail_effect] Error 1

The error happens because in this Makefile header files are in the
target dependencies, so they are added to the compilation command, but
clang does not support that when compiling and linking in the same
command.

Also take care of using LIKN.cpp to link the program, as it is a C++
program.