implement blackhole filters for logwatch, and stop applying filters after the first hit

implement console_print and log_set_func

implement nexus_lua_eval

have logwatch_conf_filter replace any old filter with the same name, and move irc_log.sql to modules/

update TODO, partially update error.c, rename module_get to modules_get, update config.lua

implement logwatch_chan.c, logwatch_chan_msg, logwatch_on_error

implement logwatch_source names, and logwatch_chan