Log Message:
Update sysutils/capistrano to 2.5.21

Upstream changes:

## 2.5.21 / April 6 2011

* Fixed to follow best-practice guidelines from Bundler (Ben Langfeld)
* No longer force a gemset for Capistrano development. (Ben Langfeld)

## 2.5.20 / March 16 2011

  * `deploy:migrations` will now always operate on the latest_release, not
current_release (Mike Vincent)
  * Adds a check for the presence of `rsync` when using the copy strategy with
`rsync`. (Chris Griego)
  * Do not try to look up the `:release_path` on servers which are defined
`:no_release` (Chris Griego)
  * Tiny patch to the `CVS` SCM code to be Ruby 1.9 compatible (Martin Carpenter)
  * Changed the default `Git` submodule behaviour to use `--recursive`
Lighthouse Issue #176. (Lee Hambley)
  * `:public_children` can now be `set()`, the default is unchanged, thanks
(Chris Griego)
  * Fixing the load path in the default `Capfile` to search vendored/unpacked
Gems. Lighthouse Issue #174 (Mari Carmen/Rafael García)
  * Adds a `maintenance_basename` variable (default value is `maintenance`) to
allow you to set the maintenance page name (Celestino Gomes)
  * Spelling fixes in inline-documentation (Tom Copeland)
  * Make `zip` and `tar` handle symlinks the same way (zip follows symlinks by
default, tar needs the option `-h`) (Ross Cooperman)