WL#5814: Link replication as a library

Affects: Server-Prototype Only   —   Status: On-Hold

This is the last step towards making replication a library, such that the 5.6 rpl-
lib can be plugged into the 5.5 core [WL#5675].

After all other, refactoring sub-WLs of WL#5675 have been pushed, we should change 
the build process so that the replication component is linked as a library.