Conditionally includes '-fstack-protector-all' when building with Gcc

With older version of gcc supporting the flag -fstack-protector-all,
an extra dependency to libssp.so is introduced. If gcc version is
less than 4.4.0 and the build type is Release let's not include the flag.

Doing so should allow to build Release package made for distribution using older linux distro
without introducing an extra dependency.

CMakeLists.txt

@@ -255,8 +255,16 @@ SET(CTK_CXX_FLAGS "${CMAKE_CXX_FLAGS_INIT} ${VISIBILITY_CXX_FLAGS} ${COVERAGE_CX
 
 IF(CMAKE_COMPILER_IS_GNUCXX)
   SET(cflags "-Wall -Wextra -Wpointer-arith -Winvalid-pch -Wcast-align -Wwrite-strings -D_FORTIFY_SOURCE=2")
+  
   ctkFunctionCheckCompilerFlags("-fdiagnostics-show-option" cflags)
-  ctkFunctionCheckCompilerFlags("-fstack-protector-all" cflags)
+  
+  ctkFunctionGetGccVersion(${CMAKE_CXX_COMPILER} GCC_VERSION)
+  # With older version of gcc supporting the flag -fstack-protector-all, an extra dependency to libssp.so
+  # is introduced. If gcc is smaller than 4.4.0 and the build type is Release let's not include the flag.
+  # Doing so should allow to build package made for distribution using older linux distro.
+  IF(${GCC_VERSION} VERSION_GREATER "4.4.0" OR (${CMAKE_BUILD_TYPE} STREQUAL "Debug" AND ${GCC_VERSION} VERSION_LESS "4.4.0"))
+    ctkFunctionCheckCompilerFlags("-fstack-protector-all" cflags)
+  ENDIF()
   IF(MINGW)
     # suppress warnings about auto imported symbols
     SET(CTK_CXX_FLAGS "-Wl,--enable-auto-import ${CTK_CXX_FLAGS}")