Added support for Bindless texture extension,

64 bit uniforms, 64 bit buffers
Added new bindless texture example

src/osgDB/ClassInterface.cpp

@@ -58,6 +58,8 @@ public:
     virtual void writeULong( unsigned long l ) { write(l); }
     virtual void writeFloat( float f ) { write(f); }
     virtual void writeDouble( double d ) { write(d); }
+    virtual void writeInt64( long long ll ) { write(ll); }
+    virtual void writeUInt64( unsigned long long ull ) { write(ull); }
     virtual void writeString( const std::string& s ) { _str.insert(_str.end(), s.begin(), s.end()); }
     virtual void writeStream( std::ostream& (*)(std::ostream&) ) {}
     virtual void writeBase( std::ios_base& (*)(std::ios_base&) ) {}