Removed some compiler warnings found by clang

- Fixed some unitialized variables
- Removed some warnings:
  -Wno-parentheses-equality gives warnings from macro-expressions
  -Wno-string-plus-int is not a common problem and it's not trivial to
  fix it in connect

cmake/build_configurations/mysql_release.cmake

@@ -222,12 +222,12 @@ IF(UNIX)
 
   # Default Clang flags
   IF(CMAKE_C_COMPILER_ID MATCHES "Clang")
-    SET(COMMON_C_FLAGS               "-g -fno-omit-frame-pointer -fno-strict-aliasing")
+    SET(COMMON_C_FLAGS               "-g -fno-omit-frame-pointer -fno-strict-aliasing -Wno-parentheses-equality -Wno-string-plus-int")
     SET(CMAKE_C_FLAGS_DEBUG          "${COMMON_C_FLAGS}")
     SET(CMAKE_C_FLAGS_RELWITHDEBINFO "-O3 ${COMMON_C_FLAGS}")
   ENDIF()
   IF(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    SET(COMMON_CXX_FLAGS               "-g -fno-omit-frame-pointer -fno-strict-aliasing")
+    SET(COMMON_CXX_FLAGS               "-g -fno-omit-frame-pointer -fno-strict-aliasing -Wno-parentheses-equality -Wno-string-plus-int")
     SET(CMAKE_CXX_FLAGS_DEBUG          "${COMMON_CXX_FLAGS}")
     SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O3 ${COMMON_CXX_FLAGS}")
   ENDIF()