Log Message:
Update ZenTest package to 4.6.0.

=== 4.6.0 / 2011-07-22

* 6 minor enhancements:

  * Added -p (plain diff) and made -u (unified diff) the default for unit_diff.
  * Added ./tmp to default exclusions.
  * Autotest defaults unit_diff to nil now, to allow minitest's enhanced \ 
assert_equal to shine.
  * Autotest will raise if the :died handler doesn't handle the exception. \ 
(ralfebert)
  * Dropped 1.8.6 as a default tag/branch to build in multiruby.
  * autotest can now be automatically 'narrowed' on the command-line.
    * eg: `autotest lib test/test_blah.rb`

* 7 bug fixes:

  * Believe it or not... but some ppl use zentest. Fixed nested class vs module bug
  * Fix to turn on jruby's support for ObjectSpace. (stepheneb)
  * Fixed a rubygems deprecation in autotest
  * Fixed unit_diff scanning for minitest output.
  * Normalized shebangs to fix problems on windows (luis)
  * autotest/isolate.rb sets GEM_HOME as well as GEM_PATH.
  * Fixed 1.9.3 warnings.