Use compile-time paths in the manual pages

Replace the hard-coded paths for various BIND 9 files (configuration,
pid, etc.) in the man pages and ARM with compile-time values using the
sphinx-build replace system.

This is more complicated, because the restructured text specification
doesn't allow |substitions| inside ``code-blocks``, so for each specific
file we had to create own substition which is sub-optimal, but it is
only way how to do this without adding Sphinx extension.