[reSIProcate] preparing for 1.8.9

[Daniel Pocock]

I've cherrypicked some changes onto the 1.8 release branch, I've only
selected the fixes that don't impact the API

E.g. the support for reTurnServer user database files and the fix for
AfterSocketCreationFuncPtr are not on the 1.8 branch.

I'd like to release 1.8.9 tomorrow and then the
AfterSocketCreationFuncPtr fix could be released in 1.8.10 in a few weeks.

Does anybody have any other suggestions about urgent things to include
in the release?

Regards,

Daniel