A long PREFIX variable (to configure) will result in very long
LOCALSTATEDIR, which when concatenated with lib/ganeti/ (and even more
items under it) will go over the 80 char line length we enforce in the
man checker.

To workaround this, we change two things:

- use a specific REPLACE_VARS_MAN which adds breaking points after each
  slash in paths
- replace some <filename> entries with <literallayout> so that docbook
  generates a non-fill block around them (only a few cases need this
  after the breaking points are added

Note that with normal prefixes (e.g. / or /usr/local) this won't happen.

The patch also fixes a wording in the watcher man page.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>