Update lib installation path (multiarch portability).

CMakeLists.txt

@@ -49,7 +49,7 @@ GENERATE_CONFIGURATION_HEADER(
 
 # FIXME: to be changed into lib/dynamic-graph
 # to avoid name collision when installing dynamic-graph in /usr.
-SET(PLUGINDIR "lib/plugin")
+SET(PLUGINDIR "${CMAKE_INSTALL_LIBDIR}/plugin")
 
 # Add extra keys to pkg-config file to export the location of the
 # plug-in directory in a robust manner.

src/CMakeLists.txt

@@ -63,7 +63,7 @@ IF (UNIX AND NOT APPLE)
 ENDIF (UNIX AND NOT APPLE)
 
 INSTALL(TARGETS ${LIBRARY_NAME}
-  DESTINATION lib)
+  DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
 ####################################
 ### Plugins