added script to determine current version

if exactly on tag, it returns the tag itself, ex.: 4.0.2
otherwise it returns the incremented last tag plus the
current date, ex.: 4.0.3_20131112

It works great with the update version script
ex.: ./update-version $(./get_version)
which is used for automatic builds.
removed some autogenerated files

these files are autogenerated and should therefor not be included in the repository.
Fix daemon_dumps_core on Linux when started as root

Under Linux, systems calls that manipulate UIDs and GIDs reset the
process dumpable flag to 0. When Naemon is started as root it drops
privileges using setuid/setgid, preventing core dumps from being
produced regardless of the value of daemon_dumps_core. This patch fixes
that by calling prctl() in drop_privileges().

Signed-off-by: Adam James <adam.james@transitiv.co.uk>