Join delay

[polyzen]

Equivalent WeeChat option:

irc.server_default.command_delay: delay (in seconds) after execution of command and before auto-join of channels (example: give some time for authentication before joining channels) [default: 0, values: 0 ... 3600]

Alternative solution to #166 for joining +r channels. Turns out you can also identify during connection if you do it via the password option, eg. setting it to <account>:<password> for Freenode. Thanks @panicbit.