Log Message:
update net/unison-devel to 2.27.10

   Changes since 2.17:
     * The native OS X user interface has been enormously improved by Ben
       Willmore and Trevor Jim.
     * The backup functionality has been completely rewritten. The
       external interface has not changed, but numerous bugs, irregular
       behaviors, and cross-platform inconsistencies have been corrected.
     * Some important safety improvements:
          + Added a new mountpoint preference, which can be used to
            specify a path that must exist in both replicas at the end of
            update detection (otherwise Unison aborts).
          + The confirmation of "big deletes" is now controlled by a
            boolean preference confirmbigdeletes. Default is true, which
            gives the same behavior as previously.
          + If Unison is asked to "follow" a symbolic link but there is
            nothing at the other end of the link, it will now flag this
            path as an error, rather than treating the symlink itself as
            missing or deleted.
     * Smaller changes:
          + Added forcepartial and preferpartial preferences
          + Refined debugging code so that the verbosity of individual
            modules can be controlled separately. Instead of just putting
            '-debug verbose' on the command line, you can put '-debug
            update+', which causes all the extra messages in the Update
            module, but not other modules, to be printed. Putting '-debug
            verbose' causes all modules to print with maximum verbosity.
          + Rewrote some of the merging functionality, for better
            cooperation with external Harmony instances.
          + Changed the temp file prefix from .# to .unison.
          + Compressed the output from the text user interface
          + Added .mpp files to the "never fastcheck" list
     * Many small bugfixes, including:
          + Fixed a bug that would occasionally cause the archives to be
            left in non-identical states on the two hosts after
            synchronization.
          + Fixed a bug that prevented Unison from communicating
            correctly between 32- and 64-bit architectures.
          + Set read-only file to R/W on OSX before attempting to change
            other attributes.
          + Fixed bug resulting in spurious "Aborted" errors during
            transport (thanks to Jerome Vouillon)
          + Enable diff if file contents have changed in one replica, but
            only properties in the other.
          + Removed misleading documentation for 'repeat' preference.
          + Fixed a bug in merging code where Unison could sometimes
            deadlock with the external merge program, if the latter
            produced large amounts of output.
          + Workaround for a bug compiling gtk2 user interface against
            current versions of gtk2+ libraries.
          + Added a better error message for "ambiguous paths".
          + Squashed a longstanding bug that would cause file transfer to
            fail with the message "Failed: Error in readWrite: Is a
            directory."