tigefa4u projects Trac

Move the DB schema classes `Table`, `Column` and `Index` from `trac.db_default` to `trac.db`.

If no dimensions for the logo image are specified in [wiki:TracIni trac.ini], don't include the `width` and `height` attributes in the generated HTML, especially not with the values from the default configuration. This lets the browser get the proper dimensions from the image itself. Closes #1862.

Don't include CC field in ticket notifications; also, make the last field wrap correctly.

Make the ''Assign to'' field optional so that tickets can be assigned to the default owner. Closes #1957.

Fix handling of empty query string in search. Closes #1959.

Ignore `*.pyc` files in `trac.versioncontrol.web_ui` package.

Added a new config option to configure the maximum html preview file size. Closes #854.

The attachment file size was not alwaus correctly calculated. Closes #1921.

Fix daemon mode for `tracd` on Unix. Thanks to Yun Zheng Hu for the patch.

`versioncontrol` sub-system refactoring: `LogModule` was extracted in its own `log.py` file. The common utility functions have been extracted as well in `web_ui/util.py`.