Currently wkcmake is overriding compile settings setup by CMake.
1) CMake has improved a lot since the beginning of WkCMake, and overriding the compile and linkage option might not be necessary anymore
2) We may want different option of compilation for different projects ( even if in the same wkcmake run - should be done with add_subdirectory ).

Since we have only one main target per project, we need to use per target compilation option.
Something like :
set_target_properties(myexe_target PROPERTIES COMPILE_FLAGS "-Wall")

This way we can also avoid overriding global cmake options, and keep reasonable defaults for other targets.