Move to a component / helper based system for the gh issues

[mariosant]

The template that will hold the issues should be more or lesss in the following form:

{{# each issues }}
  {{> githubIssue id=this.id}}
{{/each}}

So we need to create the issues helper which will fetch the project's issues and will return an array that can be iterated and a githubIssue component which will render and handle the actual issue.

• issues helper
• githubIssue component