Do not expose a parameter, as index can be reconstructed from data anyway.
Rotating is anyway needed as index backup can take a significant amount of
space for rare practical use.
Also, remove this point from TODO.

I reviewed parameters (both in code and in documentation) and think they are
now consistent and sane enough to not block a merge.

Balancer parameters were and are not supported, so this compatibility
breakage is not important.
The goal of this change is to make balancer parameter layout consistent
with other software-types.
Also, balancer's base TCP port is not taken from empty-string parameter
anymore.

They contain section references, not immediate values, so they are intended
to be evaluated by buildout and hence must not be escaped.

Test node now requests them.

Not perfect yet, as some strings end in configuration files for example
and need escape mechanisms aware of individual configuration file syntaxes.

also add mroonga-4.00-mariadb-10.0.9.patch.

Use more recently versions of PyOpenSSL requires cryptograpic egg. The cryptograpic is
incompatible with package generation because it don't cache files in the right way.