1.0b4

Another beta. Things feel a good deal more solid now.

• Unknown command line options are handled better.
• -? option added, which prints a usage string.
• Dwarf Fortress fonts should actually be supported now.
• A buffer overflow in one code path of the connection dialog has been fixed.
• The Enter key can now be used to speed through the connection dialog.
• The client no longer uses excessive CPU. (I'm disappointed by how long it took me to notice this was happening.)