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.

lib/gollum.rb

@@ -1,11 +1,15 @@
 # stdlib
 require 'digest/md5'
+require 'ostruct'
 
 # external
 require 'grit'
 require 'github/markup'
 require 'sanitize'
 
+# ruby 1.8 compatibility
+require 'gollum/ruby1.8'
+
 # internal
 require 'gollum/pagination'
 require 'gollum/wiki'