Add window levels, status bar, UTF-8 input, charset conversion

- Isolated window levels with 500-line scrollback per window
  - Window 1: status + private messages
  - Windows 2-9: channels
- Status bar showing window, channel, nick prefix, channel modes
- Automatic charset conversion (UTF-8/UTF-16 -> ISO-8859-1 on wire)
- UTF-8 aware input editing with Ctrl-A/E/U/K/Y
- CTCP VERSION reply with real OS info from uname()
- Real name from passwd GECOS field
- SIGWINCH handling for terminal resize
- Ctrl-C quit confirmation (y + Enter)
- /whois, /wii, /mode, /quit with default reason
- Green prompt, timestamps on all messages

.gitignore

@@ -0,0 +1,2 @@
+*.o
+irc