Add basic template support

[miroslavrussev]

This adds basic HTML template support for image and sprite elements by adding two new options to the global settings.

emojione.spriteTemplate = '<span class="emojione emojione-{{size}}-{{category}} _{{code}}" {{title}}>{{alt}}</span>';
emojione.imageTemplate = '<img class="emojione" alt="{{alt}}" {{title}} src="{{src}}"/>';

Current possible replacements are:
{{src}}
{{size}}
{{category}}
{{code}}
{{title}}
{{alt}}