Normalize the allowed paths as well (fix Windows breakage)
Stop using property listener for fgValidatePath
Fix typo, thanks to Markus Wanner
Fix hang in Nasal->C++->Nasal calls
FileDialog: remove WindowsFileDialog (fix bad merge)
FGRouteMgr: call load/save dialogs from C++, to allow any filename
FileDialog: add createFileDialog
FileDialog: add requireSecureFromNasal