@todo: manage instances in /etc/tarantool

Thanks for Anatol Pomozov

Hat tip to Alexey Panfilov

Make w3c isopub.ent entity files available locally,
since it is part of nobody-knows which package on Ubuntu,
and may be missing completely on other distributions.

On Ubuntu 13 even though it is part of mathml, it's not listed
properly in /etc/xml/catalog apparently.

This fixes xsltproc warnings and speeds up manual generation
significantly.

https://bugs.launchpad.net/tarantool/+bug/1200228
Remove the regression I introduced when trying to be to smart when
comparing integer numbers.

Numeric comparison is not memcmp compatible on x86, and I don't
know what I was smoking when I wrote a test which proved it wrong.

Apparently until I stop bullshitting ppl in the tagline I won't get
my hands on to finishing this feature (been 6 months since it was on a
branch).

Remove Debian Squeeze support.