Log Message:
Update seahorse to 2.26.0.

pkgsrc changes:

    * add net/avahi dependency to enable key sharing support

Changes between 2.24.0 and 2.26.0:
==================================

    * Searching by key identifiers now shows results.
    * Disable interactive tree search in key manager.
    * Add libcryptui documentation.
    * Remove use of GTK+ deprecated symbols.
    * Allow creation and deletion of keyrings from main GUI.
    * Only autostart seahorse-daemon when key sharing is enabled.
    * seahorse-daemon registers with session manager properly.
    * Remove bits of libcryptui	that are now handled by the gcr library
      from gnome-keyring.
    * Tons of other fixes and changes.