[sr-dev] Registrar updates

[Olle E. Johansson]

Kamailians,

I’ve added two patches to the registrar module:

- a new value to the XAVP created if you’ve set the xavp_rcd modparam to reveal the actual
  expiry value stored in the location database. In some cases, Kamailio will not accept the one
  provided by the client and respond with another value - this is that value
  https://www.kamailio.org/docs/modules/stable/modules/registrar.html#registrar.p.xavp_rcd

- a new flag to save() to NOT apply variation set by default_expiry_range and expiry_range. 
  This is handy if you replicate registrations - the second server needs to save the value sent by the first one
  and not change it once again.

Both of these patches work for me, but I would be happy if someone else could test as well.
If you find a problem, please open an issue in the bug tracker and I’ll look at it.

Thanks
/O