The recent 2.3beta versions have a menu item
"Wiki"->"Maintenance"->"Update ext. modif. wiki files" to check for changes.
Moreover, in the options dialog, options page "Current Wiki"->"On Open" there is
entry "Rebuild" which can be set to "Update ext. mod. files" to always check for
changes when opening the wiki.
At the moment this only affects wiki page files, not other files e.g. for
functional pages.
Michael