Update hoe pacakge to 2.9.4.

Update hoe pacakge to 2.9.4.

=== 2.9.4 / 2011-04-01

* 1 minor enhancement:

  * check_manifest now fails when there is a diff. AKA, drbrain was
    lazy and it is somehow my fault. If anything, it is jbarnette's
    fault for not building any brains into hoe-git the way that my
    hoe-perforce plugin works. I mean, c'mon... how hard is it to
    validate the manifest before you release? I do it all the time
    and twice on sundays. BAH! Damn kids! Get off my lawn!

=== 2.9.3 / 2011-04-01

* 1 minor enhancement:

  * Cleanup for rubygems 1.7 deprecations

=== 2.9.2 / 2011-03-31

* 7 minor enhancements:

  * Added :none as a testlib option to let you do whatever you want. (phiggins)
  * Added Hoe#dependency(name, version, type = :runtime) for cleaner hoe specs.
  * Added NOSUDO option to `rake gem_install`. (nihildeb)
  * Include Rake::DSL to support future versions of rake
  * Multiruby now skips mri_trunk if multiruby_skip includes 1.9
  * Test#make_test_cmd now sorts test files (mostly for testing)
  * Try using psych before syck.

* 3 bug fixes:

  * Clean generated extension library too
  * Fixed a bug with sow -d or -t
  * Fixed plugin activation via ~/.hoerc. (ged)