tigefa4u projects Trac

Should fix #3093

Wiki diff style fix (follow-up to CSS change done in r3005)

Put the `[[InterTrac]]` macro near the top of the InterTrac page

Some cleanups for the Attachment code, in particular, don't use the env.href anymore.

Simple fix for the `ImageMacro` code introduced in [milestone:0.9.5], which failed to handle the size specified with "%". Reported in #3108.

Fixes the `ImageMacro` bug w.r.t. specifying size with "%", plus added unit-tests for macros (only for `ImageMacro` so far). Closes #3108.

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.