Add COMPILE_FLAGS argument to SEMMacroBuildCLI

[finetjul]

Sometimes it might be useful to disable warnings when compiling a CLI.
The naive manual solution to call set_target_properties(${MODULE_NAME}Lib PROPERTIES COMPILE_FLAGS "-Wno-overloaded-virtual") fails because "-Dmain-=ModuleEntryPoint" is no longer defined.

[jcfr]

I am closing this issue. CMake provides the following command to achieve what is described:

set_property(
  TARGET ${MODULE_NAME}Lib
  APPEND PROPERTY COMPILE_FLAGS "-Wno-overloaded-virtual"
  )

Using set_property specifying APPEND is the key.

See also https://cmake.org/cmake/help/v2.8.6/cmake.html#command:set_property