//! Add a filesystem extension.
	//! \param ext The extension.
	//! \return True on success, false on failure.
	virtual bool addFileSystemExtension(IFileSystemExtension* ext);

	//! Add a filesystem extension (and then drop() it once).
	//! This allows the user to avoid dropping it himself.
	//! \param ext The extension.
	//! \return True on success, false on failure.
	virtual bool addAndDropFileSystemExtension(IFileSystemExtension* ext);

	//! Remove a filesystem extension.
	//! \param ext The extension.
	virtual void removeFileSystemExtension(IFileSystemExtension* ext);

	//! Remove a filesystem extension by its identifier.
	//! \param identifier The identifier (e.g. "zip").
	virtual void removeFileSystemExtension(const c8* identifier);

	//! Remove all filesystem extensions.
	virtual void removeAllFileSystemExtensions();
	
	//! Get a filesystem extension by its identifier.
	//! \param identifier The identifier (e.g. "zip").
	virtual IFileSystemExtension* getFileSystemExtension(const c8* identifier);

	//! Add a virtual filesystem.
	//! \param filename A string of the form "[id:]filename.ext". The part in barckets is optional
	//! (and the brackets should not be typed). "id" (if provided) is the 
	//! identifier of a previously added filesystem extension.
	//! Examples: "/some/real/path" or "zip:some_zip_archive.pak".
	//! \param ignoreCase: If set to true, files should be accessed without
	//! writing all letters in the right case (if supported by the extension).
	//! \param ignorePaths: If set to true, files should be accessed
	//! without their complete path (if supported by the extension).
	//! \return True if it was succesfully opened by one of the registered filesystem extensions,
	//! false if not.
	virtual bool addVirtualFileSystem(const c8* filename, bool ignoreCase = false, bool ignorePaths = false);
	
	//! Remove a virtual filesystem.
	//! \param filename A string of the form "[id:]filename.ext". The part in barckets is optional
	//! (and the brackets should not be typed). "id" (if provided) is the 
	//! identifier of a previously added filesystem extension.
	//! Examples: "/some/real/path" or "zip:some_zip_archive.pak".
	//! \return True if it was succesfully removed by one of the registered filesystem extensions,
	//! false if not.
	virtual bool removeVirtualFileSystem(const c8* filename);