The option can be used as a replacement of 'host' option
when several (sub)domains are needed to be registered for the module.
Note that you cannot combine both 'host' and 'hosts' in the config
because 'host' option is of a higher priority. Example:
mod_pubsub:
...
hosts:
- "pubsub1.@HOST@"
- "pubsub2.@HOST@"
Fixes#1883
The changes are very similar to those from previous commit:
* Now there is no need to pass validating function in
gen_mod:get_opt() and gen_mod:get_module_opt() functions,
because the modules' configuration keeps already validated values.
* New functions gen_mod:get_opt/2 and gen_mod:get_module_opt/3 are
introduced.
* Functions gen_mod:get_opt/4 and get_module_opt/5 are deprecated.
If the functions are still called, the "function" argument is
simply ignored.
* Validating callback Mod:listen_opt_type/1 is introduced to validate
listening options at startup.
Now 'From' and 'To' arguments must be omitted in functions
and structures related to routing.
The commit deprecates the following functions:
ejabberd_router:route/3 in favor of ejabberd_router:route/1
ejabberd_router:route_error/4 in favor of ejabberd_router:route_error/2
ejabberd_local:route_iq/4 in favor of ejabberd_local:route_iq/2
ejabberd_local:route_iq/5 in favor of ejabberd_local:route_iq/3
The format of {route, From, To, Packet} is changed in favor of {route, Packet}
