catch specific signals at once, using hook_signal

[weechatter]

Feature description

with hook_signal you can catch one signal or you can use a wildcard to catch more signals at once.
But it would be fine to catch only specific signals, e.g. window_switch;buffer_switch

hook = weechat.hook_signal("window_switch;buffer_switch", "my_signal_cb", "")

[flashcode]

I'm implementing this and doing it as well for hook_hsignal which works exactly the same way.

In future it could be possible to do it as well on these functions, but I doubt there are real use cases:

• hook_config
• hook_modifier
• hook_info
• hook_info_hashtable