Escaping is right, but "raw" context entry type does not de-serialise, so
deadlock debugger password was stored in an unintended format. Moving
deadlock_debugger_password to a buildout section involves required magic.
Move other parameters for consistency.
Also, honour deadlock_path parameter, which was previously ignored.

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.

inkscape seems not to start with glib 2.39 or later like :
futex(0x7fff41df100c, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 1, NULL, 7ffedf9a4a00) = -1 EAGAIN (Resource temporarily unavailable)

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.