Allow running plugin_installer plugin from build dir

See http://hub.qgis.org/issues/5879

Author: Sandro Santilli

python/plugins/plugin_installer/CMakeLists.txt

@@ -25,8 +25,4 @@ PYQT4_WRAP_UI(PYUI_FILES
 
 PYQT4_ADD_RESOURCES(PYRC_FILES resources.qrc)
 
-ADD_CUSTOM_TARGET(pluginstaller ALL DEPENDS ${PYUI_FILES} ${PYRC_FILES})
-
-INSTALL(FILES ${PYUI_FILES} DESTINATION ${QGIS_DATA_DIR}/python/plugins/plugin_installer)
-INSTALL(FILES ${PYRC_FILES} DESTINATION ${QGIS_DATA_DIR}/python/plugins/plugin_installer)
-INSTALL(FILES ${INSTALLER_FILES} DESTINATION ${QGIS_DATA_DIR}/python/plugins/plugin_installer)
+PLUGIN_INSTALL(plugin_installer . ${PYUI_FILES} ${PYRC_FILES} ${INSTALLER_FILES})