Clean up of TXP plugin for IRIX build.

src/osgPlugins/txp/ReaderWriterTXP.cpp

@@ -35,7 +35,7 @@ public:
         std::string foundname =  osgDB::findFile(filename.c_str());
         if( !foundname.empty())
         {
-            if (archive.OpenFile(foundname))
+            if (archive.OpenFile(foundname.c_str()))
             {
                 notify(INFO) << "TXPFile::loadFile(): loading archive: "
                     << foundname << std::endl;

src/osgPlugins/txp/TrPageArchive.cpp

@@ -39,7 +39,7 @@ TrPageArchive::~TrPageArchive()
 {
 }
 
-bool TrPageArchive::OpenFile(const std::string &file)
+bool TrPageArchive::OpenFile(const char* file)
 {
     m_alternate_path = osgDB::getFilePath(file);
     std::string name = osgDB::getSimpleFileName(file);

src/osgPlugins/txp/TrPageArchive.h

@@ -44,7 +44,7 @@ namespace txp
         ~TrPageArchive();
         
         // open archive file
-        bool OpenFile(const std::string& filename);
+        virtual bool OpenFile(const char* file);
         
         /// Load and create textures and materials
         void LoadMaterials();

src/osgPlugins/txp/TrPageParser.h

@@ -27,22 +27,12 @@
 #include <osg/Vec2>
 #include <osg/StateSet>
 #include <osg/ref_ptr>
+#include <osg/Texture>
+#include <osg/Group>
+#include <osg/StateSet>
 #include <vector>
 #include "trpage_read.h"
 
-// forward declarations
-namespace osg
-{
-    class Group;
-    class Node;
-    class Material;
-    class Texture;
-    class TexEnv;
-    class Light;
-    class Transparency;
-    class CullFace;
-};
-
 namespace txp
 {
     class TrPageParser : public trpgSceneParser