Rewrote the FileUtils support for data and library file paths, moving the

storage of the path lists into osgDB::Registry, and changed the data
structor from a char* to a std::deque.  Changed a names of couple of the
convinience functions in osgDB/FileUtils to better reflect the two
public FilePathList's - DataFilePathList and the LibraryFilePathList.

Added support into the osgDB::Registry::readNode/Image/Object methods
for pushing and popping the path of the current file being loaded.

src/osgPlugins/txp/ReaderWriterTXP.cpp

@@ -32,7 +32,7 @@ public:
     {
         Group* ret = 0; 
         // search the SGL data path
-        std::string foundname =  osgDB::findFile(filename.c_str());
+        std::string foundname =  osgDB::findDataFile(filename);
         if( !foundname.empty())
         {
             if (archive.OpenFile(foundname.c_str()))