editor: handle property changes to links. Previously, property changes to links caused 'link ' to be prepended to the link destination. Removing a line that prepended it in Revision::set() appears to fix it. In these cases, the "file marked as link, but contains data" warning might be triggered. This should be safe, so it's lowered to a note and the language made less conclusive. In order to test this, extra revisions are added to the 'symlinks.svndump' fixture. As one of the new revisions add a link that points to 'link to this', a check that asserted that link destinations must not start with 'link ' was removed. This change is safe, as the test later on asserts exact equality with the contents of the 'links' dictionary.

--- a/hgsubversion/editor.py
+++ b/hgsubversion/editor.py
@@ -38,8 +38,6 @@ class RevisionData(object):
         self.exception = None
 
     def set(self, path, data, isexec=False, islink=False):
-        if islink:
-            data = 'link ' + data
         self.files[path] = data
         self.execfiles[path] = isexec
         self.symlinks[path] = islink