1. Move the declaration of osrfRouter out of the header

1. Move the declaration of osrfRouter out of the header
and into osrf_router.c.  There's no need for any other
source file to know about the internals.

2. Eliminate the ROUTER_SOCKFD macro in favor of the new
client_sock_fd() function.  Reason: it needlessly coupled
the osrfRouter and osrfRouterClass structures by requiring
each of them to have a member named "connection".

3. Further tinkering with the comments.

M    src/router/osrf_router.h
M    src/router/osrf_router.c

git-svn-id: svn://svn.open-ils.org/OpenSRF/trunk@1838 9efc2488-bf62-4759-914b-345cdb29e865