tigefa4u projects Trac

Follow-up to [2078]: adjust imports and minor cleanup.

* Move some stuff from {{{trac.web.main}}} into {{{trac.web.api}}}, such as the interfaces and the {{{Request}}} base class.
* The authentication mechanism should now be replacable. Closes #1855.
* Moved the quoting of cookie values from {{{trac.util}}} into the {{{Request}}} class.

Allow {{{Href}}} objects to be called without args to get the base URL.

More flexible way to hide some properties in the source browser and the changeset view, using TracIni (`[browser]` section, `hide_properties` key and a comma-separated list of SVN properties). Fixes #1896.

Hide the svk:merge property in the browser and changeset view, closes #1896.

Handle wiki tables with trailing white-space better, closes #1833.

Escape links in a couple of places. See #1927.

Allow format parameter in attachment links. Closes #1929. Thanks to Shunichi Goto for the patch. Also, added unit tests for the attachment wiki links.

Wiki page version number should start at 1 instead of 0.

* Escape author in RSS feed. Fixes #1912.
* Some minor validation fixes. Closes #1926 and #1928.