Add uninstall target in cmake

CMakeLists.txt

@@ -335,6 +335,12 @@ else (DOXYGEN_FOUND)
 	message("Doxygen need to be installed to generate the doxygen documentation")
 endif(DOXYGEN_FOUND)
 
+# uninstall
+add_custom_target(uninstall
+  COMMAND cat ${PROJECT_BINARY_DIR}/install_manifest.txt | xargs rm -rf
+  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+)
+
 # XXX for a normal full distribution we'll need to figure out
 # XXX how to build both shared and static libraries.
 # Probably leverage that to build a local VALGRIND=1 library for testing too.