Get human-readable error information.
Get the last PhysicsFS error message as a human-readable string. This will be empty if there's been no error since the last call to this function. The pointer returned by this call points to an internal buffer. Each thread has a unique error state associated with it, but each time a new error message is set, it will overwrite the previous one associated with that thread. It is safe to call this function at anytime, even before (init).
It is not wise to expect a specific string of characters here, since the error message may be localized into an unfamiliar language. These strings are meant to be passed on directly to the user.