Delete gettytab.bak and ttys_wrap, they are not needed anymore
Remove unused function color()
Sync gettytab with FreeBSD 10-STABLE, also reduce customizations, the only difference is al.Pc entry, for Pc with auto login
Sync etc/ttys with FreeBSD 10-STABLE, change default console for al.Pc and default serial for al.115200
Stop restoring gettytab.bak since it doesn't exist anymore
Stop calling auto_login() here since it's already called inside setup_serial_port()
Change default console from cons25 to xterm, while I'm here, simplify the check
Fix #3647 and other improvements:

- Remove auto_login(), now gettytab is a constant file
- Add reload_ttys(), that will send a SIGHUP to init and make it reload
  /etc/ttys
- Change serial speed on /etc/ttys when necessary
- Change console and serial auto_login on /etc/ttys when necessary
- Change default type from cons25 to xterm
Obsolete ttys_wrap and gettytab.bak
Fix typo on var name
Make proper checks to check if we should or not enable serial console