Liquid UTF-8 support

[ozeias]

Adds support for UTF-8 word characters in Ruby 1.9 that is also backwards compatible with 1.8 from #164

Before:

@template = Liquid::Template.parse("hi {{ordem_número}}")
@template.render( 'ordem_número' => '201300000000017' )
=> "hi "

After:

@template = Liquid::Template.parse("hi {{ordem_número}}")
@template.render( 'ordem_número' => '201300000000017' )
=> "hi 201300000000017"

@boourns & @Soleone & @dylanahsmith for review

[daviscabral]

👍

[Soleone]

does look good to me 👍

[boourns]

👍