tigefa4u projects Trac

Follow-up to r3339, taking into account r3241... Thanks cmlenz for being vigilant :)

Various small clean-ups in the Wiki formatter:
* break paragraphs also for the `system_message` div elements
* when calling a macro, don't scan the list of macros twice
* !InterWikiMap can be used as a dict
* lots of small improvements to the documentation
* /me added as one of the author/maintainer for the wiki code

Set a dummy log handler in case the `log_type` is not specified or not known. Fixes #3148.

Email notification: do not attempt to send a notification if no valid recipient has been found. Should fix #954
* add a new unit test

Email notification: document the new options `smtp_default_domain` and `use_short_addr`

Email notification changes:
* ensure all physical lines in a message end with the '''CRLF''' marker, to fulfill RFC2822 requirements.
* introduce support for TLS-enabled STMP server
* deprecate the "maxheaderlen" configuration option

Remove dots in heading anchor ids, as it's impractical to refer to such anchors using the Wiki TracLinks syntax (if not quoted, the link stops at the first dot in the fragment)

Refactoring of link resolvers: use `Formatter.split_link` helper method.

This opens the way to more uniform treatment of query and fragments in TracLinks.
See related #2168.

Follow-up to r3329, forgot to deprecate one kind of direct image links.

Plus some clean-ups in the `Formatter._make_..._link` methods.

No need to `unquote` the labels here, as we don't do that anymore on the targets either. Related to #747.