Ruby 1.9 compatibility

* Adds current directory to load path for tests because 1.9 does not
* Aliases String#lines to String#to_a under 1.8 to match 1.9 behavior
* Sets encoding magic comment in test file with characters outside ascii
* Require 'ostruct' explicitly

This depends on a patch to Grit to have full functionality through the
whole stack.

test/test_page.rb

@@ -1,3 +1,4 @@
+# ~*~ encoding: utf-8 ~*~
 require File.join(File.dirname(__FILE__), *%w[helper])
 
 context "Page" do
@@ -109,4 +110,4 @@ context "Page" do
     footer = @wiki.page("_Footer")
     assert_nil footer.footer
   end
-end
+end