Renamed "gotty" to "tio"

Renamed to "tio" because it is shorter and this new name also more
precisely reflects what the program is - a simple TTY terminal I/O
application.

"tio" can be considered short for terminal I/O or TTY I/O or a
combination of the two, whichever you prefer.

Also, wanted to avoid naming conflicts with other projects.

src/main.c

@@ -1,7 +1,7 @@
 /*
- * Go TTY - The Really Simple Terminal Application
+ * tio - the simple TTY terminal I/O application
  *
- * Copyright (c) 2014  Martin Lund
+ * Copyright (c) 2014-2016  Martin Lund
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -21,9 +21,9 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include "gotty/options.h"
-#include "gotty/tty.h"
-#include "gotty/log.h"
+#include "tio/options.h"
+#include "tio/tty.h"
+#include "tio/log.h"
 
 int main(int argc, char *argv[])
 {