tigefa4u projects Trac

Be more robust w.r.t changesets which don't have an ''author'' value set. Thanks to ''toten'' on IRC for bringing this up.

Fix pygments rendering unit tests. They were initially written for Pygments 0.5.1. Now they're compatible with 0.7. The output still exhibits the empty span issue (see #4339).

PermissionPolicy: fixed the ticket: TracLinks unit tests. It was a bit tricky to discover that the status enum had to exist in the DB in order for the ticket status field to be retrieved correctly... (see `TicketSystem.get_ticket_fields`)

PermissionPolicy: indirect contexts can now be detected based on the length of the `permid()` tuple

Custom tab expansion for #4557, with some basic tests

PermissionPolicy: TracLinks to non-viewable tickets are shown as missing. Some unit-test updates (though there are still a few issues, will fix tomorrow).

PermissionPolicy: the !PermissionCache is again at the Request level

The Context only has a !PermissionCacheProxy for conveniently delegating calls to the actual cache. There, the permissions for the user are looked-up at most once for each context.

In order to differentiate among different "indirect" resources (e.g. attachments) that can share the same (realm,id), a new `Context.permid()` has been introduced. The default implementation should be enough to provide a unique key for the resource in the permission system. In the case of attachments for example, that key can be augmented by the parent context's key.

PermissionPolicy: several minor fixes and cleanups
- check for attachment replacement, by checking for both 'CREATE' and 'DELETE'; to make this easier, `perm.require` accepts a list of permissions
- use unqualified verbs for the wiki module
- display the Attach button on the wiki view when this is the only possible action

PermissionPolicy: as expected, the Context class can be easily used for describing "pseudo" resources

Example: for the !AuthzPolicy plugin (see sample-plugins/authz_policy.py), it is possible to configure the TracIni configuration view to be visible only to administrators, whereas the system information can be viewed by anyone.

{{{
[about:config]
@administrators = VIEW

[about:systeminfo]
* = VIEW
}}}

PermissionPolicy: merged latest changes from trunk [4590:4597/trunk]