cmake: set C/C++ standard

Avoid useless warnings

CMakeLists.txt

@@ -41,6 +41,9 @@ set(PROJECT_DESCRIPTION
   )
 SET(PROJECT_USE_CMAKE_EXPORT TRUE)
 
+SET(CMAKE_C_STANDARD 99)
+SET(CMAKE_CXX_STANDARD 98)
+
 # Do not support CMake older than 2.8.12
 CMAKE_POLICY(SET CMP0022 NEW)
 SET(PROJECT_USE_KEYWORD_LINK_LIBRARIES TRUE)