ENH: Adding implementation of shared library version support on UNIX. This addresses the feature request described in bug#32.

Modules/Platform/Linux.cmake

@@ -7,3 +7,4 @@ SET(CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS "-shared")
 SET(CMAKE_SHARED_LIBRARY_LINK_FLAGS "-rdynamic")  
 SET(CMAKE_SHARED_LIBRARY_RUNTIME_FLAG "-Wl,-rpath,")
 SET(CMAKE_SHARED_LIBRARY_RUNTIME_FLAG_SEP ":")
+SET(CMAKE_SHARED_LIBRARY_SONAME_FLAG "-Wl,-soname,")