tigefa4u projects Trac

Merging minor changes from [source:sandbox/context-refactoring]: \!SubversionAuthorizer should implement IPermissionPolicy.

Merging minor changes from [source:sandbox/context-refactoring]: clearer relative TracLinks tests

Merging minor changes from [source:sandbox/context-refactoring]: clean-up of \![[InterWiki]] macro

context refactoring: merge with trunk (r6060, r6072 and r6073)

Improved rendering of the CC: field. Fixes #6072.

Patch renderer: improve display of "meta" information about line changes, like the ''No newline at end of
file'' message. Related to #6199.

context refactoring: add an explicit `resource` parameter to `Context.__call__`.

context refactoring: fix `get-relative_url` so that it is really resource dependent (it now uses `get_url`).

Also removed left-over print statements from previous changes.

context refactoring: simplify `ResourceSystem` further

The `ResourceSystem` is no longer a default `IResourceManager` for otherwise unmanaged resources.
The default implementation for `get_resource_url` and `get_resource_description` has been moved in the helper functions `get_url` and `get_description`, respectively.

Added a few API documentation and doctests.

context refactoring: fix the handling of attachments, which was broken by the recent serie of changes.