Rewrite to accomodate many new things

Recoded structure,
Added simple xhr response error handling (401,404,500,...) via promises,
Added several new options (prefix, urls, loadFromSearch, extraAnnotationData),
Added custom url id replacement (/annotation/:id) capability
Updated to reflect the new code
Merge pull request #1 from DavidHavl/master

Enhancements to the code.