Zope 2.13: SiteAccess: Make VirtualHostMonster support IPv6

from https://bugs.launchpad.net/zope2/+bug/699865 :

VirtualHostMonster does not work with IPv6 named hosts.

In case of such rewrite configuration:

RewriteRule (.*) http://10.0.243.129:9280/VirtualHostBase/https/[%{SERVER_ADDR}]:4080$1 [L,P]

When SERVER_ADDR is fd00::74ba VirtualHostMonster dies with:

Traceback (most recent call last):
  File "/eggs/Zope2-2.12.14-py2.6-linux-x86_64.egg/ZPublisher/BeforeTraverse.py", line 145, in __call__
    meth(*(container, request, None)[:args])
  File "/eggs/Zope2-2.12.14-py2.6-linux-x86_64.egg/Products/SiteAccess/VirtualHostMonster.py", line 154, in __call__
    host, port = host.split(':')
ValueError: too many values to unpack

This is because IPv6 addresses contain ":" in them.

--
This is backport of https://github.com/zopefoundation/Zope/pull/314 to
2.13 branch

This also include part of:
2e9d01ea - flake8 Products/Shared/ZTUtils.
removing test_suite function from the test

* Port the fix for #375 to Zope 2.13.
* Fix version ranges to be able to run buildout.

[skip ci]

(cherry picked from commit e1baf42f591101f04b5dfc2366d1c17d41dd2fe5)

* Add tests to check the DoS prevention code.

* Add `._pasteObjects()` to be able to paste objects without limits.

Fixes #217.

Test that `str.format` checks security for accessed keys and items.

The PR was merged, but we still need a checkout at this moment.

The real fix is in the AccessControl package, which we checkout on a specific branch here.
Part of PloneHotfix20171128.

Make Redirect unavailable as url [2.13]

Skip IPv6 tests on Travis, as it is not supported.

Using the previously described variant using the index led to a broken installation because `pip` installs `Products.ZCatalog` 4.x. It expects to find `products.zcatalog` in the index. (Even downgrading to pip 1.5 does not help.)

This closes #194.