Remove C89 restriction for clang (#303)

Author: marisn

CMakeLists.txt

@@ -82,7 +82,7 @@ if(CMAKE_COMPILER_IS_GNUCC)
 endif()
 
 if(CMAKE_C_COMPILER_ID MATCHES "Clang")
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror=declaration-after-statement -std=c89 -Wno-comment")
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror=declaration-after-statement -Wno-comment")
 endif()
 
 #options suported by the cmake builder