Core/Build: Fix compile under Ubuntu 13.04 and openSUSE 12.3 (and probably other new distros)

Closes #9832
Closes #9740

CMakeLists.txt

@@ -51,6 +51,8 @@ include(CheckPlatform)
 find_package(PCHSupport)
 find_package(ACE REQUIRED)
 find_package(OpenSSL REQUIRED)
+find_package(Threads REQUIRED)
+
 if( NOT USE_MYSQL_SOURCES )
   find_package(MySQL REQUIRED)
 endif()