add_watch_full

Description:

public uint add_watch_full (int priority, StreamIOCondition cond, owned StreamIOFunc func)

Adds a watch for this to the mainloop

this	the stream
priority	the priority of the Stream source
cond	the conditions to watch for (bitfield of StreamIOCondition)
func	the function to call when the condition is satisfied
notify	the function to call when the source is removed
opaque	user data to pass to `func`

the event source id