make Baroes packaging more Debian compliant

install READMEs as docs into bareos-doc,
set Standards-Version: 3.9.5,
do not ship .la files, as suggested in Policy 10.2,
remove dependency to hostname package, as it is always installed,
let bareos-dbg properly depend on all the packages it proves symbols for,
depending on the arch:all bareos package is wrong in several ways:
- using binary:Version for an arch:all package will cause problems
  with binNMUs (https://wiki.debian.org/binNMU)
- it will force everyone to install ALL packages when debugging a
  (e.g.) filedaemon only problem
add debian/watch file,
depend on bsd-mailx | mailx instead of only mailx,
some changes to the descriptions (wording, fixing too long Description lines),
drop autoconf/config.log and add it to gitignore,
install bat help in a subfolder of htmldir