tigefa4u projects Trac

A few minor cleanups for the DatabaseBackend refactoring

Make it easier to remove the availability of the ''Ticket details'' event filter in the TracTimeline.

By default, it is disabled, but it can be restored by using a new config entry in TracIni:
{{{
[timeline]
ticket_details = yes
}}}

Also, even if the feature is enabled, the filter itself will be inactive by default
(i.e. the ''Ticket details'' check box is left unchecked; the user can of course
decide to use it).

In a future release, the `trac.ticket.UpdateDetailsForTimeline`
will be merged with the base ticket event provider, so don't
rely on the presence of that component to enable/disable the feature.

Fixes #1895.

Improve compatibility of the Roadmap iCalendar format with Outlook. Fixes #1988. Thanks to markus for the patch.

Detect unicode BOMs in files that are to be diffed, and adjust the charset accordingly for transcoding to UTF-8. Should fix #2218.

Remove unused import, cleanup docstrings.

Remove obsolete dummy component.

Strip leading and trailing whitespace from the names of milestones, versions, components, etc. I.e. and ticket field values that get used in a `<select>` control. Fixes #1344.

Homogenize the display of columns in the Browser and Log Revision views

DatabaseBackend refactoring: the old db.py file has been split in several files
now placed in the trac/db subfolder.

Also, a new `IDatabaseBackend` interface has been defined,
and this is used for better dispatching from the database connection string
to the appropriate backend.

This greater flexibility would allow to use the pysqlite1 binding
for one environment and the pysqlite2 binding for another, for example.

While the changes were primarily done for cleaning up the current implementation,
this will also make it easier to add new database backends.

Created a branch for cleaning-up the code related to the DatabaseBackend