tigefa4u projects Trac

in tracd use the WSGI middleware for handling the Trac environment config in HTTP mode

PermissionPolicy: Ported timeline to new permission system. Adds `timeline_event` and `timeline_filter` ''resource'' types.

Should fix #3057.
* Fix up another trouble with quoted-printable encoding
* Nicer usage of Python email library
* Needs some cleanup for long headers

WorkFlow: Trunk merge log:trunk@...:3228

PermissionPolicy: Trunk merged log:trunk@...:3228

PermissionPolicy: Fixed typo in wiki module and applied policy to search filters earlier.

DiscussionPolicy:

* Migrated attachment module. Attachment resource ID's are in the form `('attachment', (<parent-type>, <parent-id>, <filename>))`.
* Also updated ticket and Wiki interfaces to check permissions when viewing attachments.
* Migrated search module. Added a variety of control points, including `search_filter`, `search_terms` and `search_result`.
* Migrated about module. Resource ID's are in the form `('about', <page>)`.

don't open the file inside the try/finally since you can't run `close` it `open` failed (see r3213 and fix in r3224 for #3063)

Fixed another situation where `mime_type` could have been `None` in attachment preview.

Fix code hastily written in env.py... Should close #3063.