shared modules are not linked so do not use lib prefix

Modules/Platform/Windows-gcc.cmake

@@ -3,6 +3,7 @@ SET(CMAKE_STATIC_LIBRARY_PREFIX "lib")
 SET(CMAKE_STATIC_LIBRARY_SUFFIX ".a")
 SET(CMAKE_SHARED_LIBRARY_PREFIX "lib")          # lib
 SET(CMAKE_SHARED_LIBRARY_SUFFIX ".dll")          # .so
+SET(CMAKE_SHARED_MODULE_PREFIX "")
 SET(CMAKE_DL_LIBS "")
 SET(CMAKE_SHARED_LIBRARY_C_FLAGS "")            # -pic 
 SET(CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS "-shared")       # -shared