Added an `export:<rev>:<path>` TracLinks for getting access to files in the repository using the raw format.
Added an `export:<rev>:<path>` TracLinks for getting access to files in the repository using the raw format.

This goes together with a new URL format `/export/<rev>/<path>`, which is especially useful for browsing HTML documents stored in the repository and getting the relative links (embedded images, stylesheets, etc.) to work as expected.

Also, this interacts better with IExplorer (fixes #3083).

git-svn-id: eda3d06fcef731589ace1b284159cead3416df9b@4242 af82e41b-90c4-0310-8c96-b1721e28e2e2

netjunki/trac-Pygit2,jun66j5/trac-ja,walty8/trac,netjunki/trac-Pygit2,jun66j5/trac-ja,jun66j5/trac-ja,jun66j5/trac-ja,walty8/trac,walty8/trac,netjunki/trac-Pygit2,walty8/trac