Log Message:
Update to 0.29.
Update p5-SVN-Mirror dependency to 0.55.

Upstream changes:

[Changes for 0.29 - 1 Feb, 2005]

* New copy_ancestors implementation for speeding up merge base lookup
  and svk info.

* Publish node signature in SVK::Editor::XD update mode.  This makes
  svk st fast the first time after checkout.

* Partially support remote copies that cross mirror anchors.

* Implement svk ci -F (and in other commands that do commit), to read
  log message from a file.

* "at / ay" in svk resolve are now "safe": they will accept the
  non-conflicting chunks from the other side, instead of overwriting
  them with theirs/yours version. [Autrijus]

* get_prompt() now uses Term::ReadKey to always read from the
  interactive terminal; this solves the problem of eg.  "svk patch -P
  - < foo.patch" clobbering the interaction. [Autrijus]

* Autovivification for mirrors now take sane defaults. [Autrijus]

* Add -C|--check-only to svk update. [Jody Belka]

* Dangling Conflict items are now reported.

* Fix a problem that 'g'-merged properties are still scheduled on
  checkout.

* Fix a problem that an already deleted directory from checkout is
  usable to be rm'ed.

* Many other minor fixes regarding error message and usability.

* General code cleanups.