tigefa4u projects Trac

Document the fact that the mimeview API has a few shortcomings which will be addressed in future releases (related to #3332)

Markup branch: migrated the attachment templates

Also:
- migrated list_of_attachments macro (Ticket template now uses it)
- made a preview_file macro (Browser template also uses it)
- some s/to_hdf/data/ renamings

Markup branch: another minor nit for the ''About'' template, no need to have ''About Trac - Trac'' for the title.

Cast timestamp strings into floats instead of ints to avoid problems with custom sql reports. Closes #3476.

Markup branch: oops, forgot to remove the intentional error I used for testing r3660...

Markup branch: migrated the error reporting template.

Also:
- restored the usage of `trac.version` vs. `chrome.version`,
as the latter didn't look so good
- introducted a configuration option for enabling the
automatic reload of templates
{{{
[trac]
auto_reload = yes
}}}

(defaults to False, but it's definitely a must while developing!)

Markup branch: merged [3600:3658/trunk]

Markup branch: the notification code now also uses Chrome().load_template, following [3655]. Also, fixed the test infrastructure so that most notification unit tests are now OK (only 3 errors left).

Markup branch: fix the wiki test cases by generating XHTML instead of HTML (when using the ''html'' wiki processor) or XML (when converting an Element to unicode)

Follow-up to r3655, got some links wrong.