Move calculation of normalised uri to the codepath where it is actually used
- this fixes a bug in the mako-render script which refuses to process a filename
  that is given as a relative path
Revert "Move calculation of normalised uri to the codepath where it is actually used"

This reverts commit 1504fc60e4b676aeec2ccc3121d7462bc885545f.
Add --template-dir option to mako-render, also allow relative paths on command line
Merged in dharland/mako/patch-fix-mako-render-relative-path (pull request #2)

Allow mako-render script to take relative path filenames