* common/const.h: Add declaration for buildid, an incrementing
build number to give finer version tracking of development code.
* server/ServerRouting.cpp: Add buildid to the server status
made available to all clients. Fix entity count in server status
as it wasn't fully added in the last change.
* server/Makefile.am, scripts/gen_buildid.py: Implement buildid
by pulling the RCS revision number out of ChangeLog from its
embedded RCS $Id$ entry.
* common/const.cpp: Remove build time and date, because they almost
never get updated here.
* scripts/gen_buildid.py: New script to generate a source file
to note the build time and date.
* server/Makefile.am: Create a new file that depends on all server
sources that contains the build time and data, and will contain
the build number.
* server/ServerRouting.cpp: Add number of entities in the world
to the server info.
