First pass of load files through an interface (to allow loading from memory, zip file etc). So instead of posix fopen/fread, using CommonFileIOInterface.

A fileIO plugin can override custom file IO operations. As a small test, load files from a zipfile in memory.
Default fileIO implementation is in examples/Utils/b3BulletDefaultFileIO.h
Affects URDF, SDF, MJCF, Wavefront OBJ, STL, DAE, images.

examples/SharedMemory/plugins/fileIOPlugin/fileIOPlugin.h

@@ -0,0 +1,24 @@
+#ifndef FILE_IO_PLUGIN_H
+#define FILE_IO_PLUGIN_H
+
+#include "../b3PluginAPI.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+	//initPlugin, exitPlugin and executePluginCommand are required, otherwise plugin won't load
+	B3_SHARED_API int initPlugin_fileIOPlugin(struct b3PluginContext* context);
+	B3_SHARED_API void exitPlugin_fileIOPlugin(struct b3PluginContext* context);
+	B3_SHARED_API int executePluginCommand_fileIOPlugin(struct b3PluginContext* context, const struct b3PluginArguments* arguments);
+
+	//all the APIs below are optional
+	B3_SHARED_API struct CommonFileIOInterface* getFileIOFunc_fileIOPlugin(struct b3PluginContext* context);
+	
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif  //#define FILE_IO_PLUGIN_H