Remove exit status check.

  Some versions of vim return non zero exit codes
  (http://tooky.github.com/2010/04/08/there-was-a-problem-with-the-editor-vi-git-on-mac-os-x.html)

lib/interactive_editor.rb

@@ -55,7 +55,7 @@ def system(file, *args)
 
     module MRI
       def system(file, *args)
-        Kernel::system(file, *args) or raise "error exec'ing #{file}: #{$?}"
+        Kernel::system(file, *args) #or raise "error exec'ing #{file}: #{$?}"
       end
     end