tigefa4u projects Trac

Before the end of a WikiFormatting, flush unfinished code blocks. Fixes #1924.

TracRevisionLog and wiki history pages can now been printed. Thanks to Tim Hatch for pointing this out and for the initial patch. Fixes #3134

SpamFilter: log rejects at the `WARN` level.

Improve the way external links are displayed. The icon now always appear on the same line as the link itself. Unit-tested adapted and, along the way, moved around a few InterTrac tests that were out of place.

fix some inconsistencies in `sorted` from 2.4 implementation:
* ''always'' return a list, not the `reversed` generator returned when
reverse-sorting without a key function
* sorting should be stable w.r.t. the `key` function. When keys were equal
it was falling back to sorting on the original value

Cleanup in email notification unit test suite:
* Fix an important issue which may have cause to use previous test results while validating email recipients
* Split notification unit tests into a set of classes for supporting SMTP basic features, and the actual ticket notification tests
* Add a non-regression test for #3101
* Fix up documentation strings

Quick follow-up for r3277, fixing the unit-tests for trac-admin.

* in `query:` links pass constructor args instead of constraints where
appropriate so duplicate keyword args aren't passed to the `href`
(fixes #2818)
* handle negative logic when displaying query checkbox fields (fixes #2994)

load the default config before creating a new `Environment` to make sure global logging settings don't cause problems (fixes #2498)

skip version conflict errors when loading plugins