converger: Add new methods to the API
converger: Add new methods to the API

This adds new helper methods to the API such as the ability to query the
set timeout, and to set the state change function after initialization.
The first makes it easier to pass in the timeout value to functions and
structs, because you don't need to pass it separately from the converger
object. The second makes it easy to specify the state change functon
when you don't know what it is at creation time. In addition, it is more
powerful now, and tells you when we converge or un-converge in case we
want to take different actions on each.

gzsierra/mgmt,gzsierra/mgmt,gzsierra/mgmt