add refute_equal to ActiveSupport::TestCase
add refute_equal to ActiveSupport::TestCase

ActiveSupport::TestCase extends Test::Unit::TestCase in Ruby 1.8,
whereas in Ruby 1.9, Test::Unit is implemented by MiniTest under the
hood. This means that ActiveSupport::TestCase in Ruby 1.8 is missing
some functions that minitest from Ruby 1.9 provides.

refute_equal is one of those missing functions in Ruby 1.8. Add it in
our test_helper.

This fixes a test suite failure in HookTest where refute_equal is an
undefined method.

gitorious/mainline,Gitorious-backup/mainline,tigefa4u/gitorious-mainline,spencerwp/mainline,spencerwp/mainline,SamuelMoraesF/Gitorious,elcom/gitorious,tigefa4u/gitorious-mainline,SamuelMoraesF/Gitorious,rae/gitorious-mainline,gitorious/mainline,SamuelMoraesF/Gitorious,Gitorious-backup/mainline,Gitorious-backup/mainline,rae/gitorious-mainline,SamuelMoraesF/Gitorious,rae/gitorious-mainline,gitorious/mainline,Gitorious-backup/mainline,tigefa4u/gitorious-mainline,gitorious/mainline,spencerwp/mainline,elcom/gitorious,elcom/gitorious,elcom/gitorious,tigefa4u/gitorious-mainline,spencerwp/mainline,rae/gitorious-mainline