Fixed page overlap for file revision links in hgweb.
This is another step to fix issue189, but currently the file revision numbers
are read as changeset revision numbers, so the link will point to the wrong
revision.
% file replaced with directory
adding a
% should fail - would corrupt dirstate
abort: file named 'a' already in dirstate
% directory replaced with file
adding a/a
% should fail - would corrupt dirstate
abort: directory named 'a' already in dirstate
% directory replaced with file
adding b/c/d
% should fail - would corrupt dirstate
abort: directory named 'b' already in dirstate