[commit] rev 391: dvc-bookmarks: Clean up nickname adding code.

Committed revision 391 to http://bazaar.launchpad.net/~toby-mi6/dvc/toby_allsopp

dvc-bookmarks: Clean up nickname adding code.

  * lisp/dvc-bookmarks.el (dvc-bookmark-partners-by-url): New function.
    (dvc-bookmarks-remove-partner): Call it.
    (dvc-bookmarks-add-nickname): Simplify by using
    dvc-bookmark-partners-by-url and dvc-bookmarks-partner-nickname.
    Report an error in case dvc-bookmarks-partner-at-point is buggy.