Add a global option to force colored output from compiler.

Taken from https://medium.com/@alasher/colored-c-compiler-output-with-ninja-clang-gcc-10bfe7f2b949

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>

modules/TDEMacros.cmake

@@ -41,6 +41,19 @@ if( NOT TDE_CMAKE_ROOT )
          CACHE FILEPATH "TDE CMake templates" )
 
   endif()
+
+
+  option( FORCE_COLORED_OUTPUT "Always produce ANSI-colored output (GNU/Clang only)." FALSE )
+  if( ${FORCE_COLORED_OUTPUT} )
+    if( "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" )
+      if( NOT "${CMAKE_CXX_COMPILER_VERSION}" VERSION_LESS "4.9" )
+        add_compile_options (-fdiagnostics-color=always)
+      endif()
+    elseif( "${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" )
+      add_compile_options (-fcolor-diagnostics)
+    endif()
+  endif()
+
 endif()