Version 0.2

* Improve templating (allow a theme to be selected and to import/export themes), ala #2 
* Create separate editor options from main GS installation, ala #1 
* Implement [`catalog_get_categories`](/lokothodida/gs-catalog/wiki/API#getting-categories), [`catalog_get_category`](/lokothodida/gs-catalog/wiki/API#getting-an-individual-category), [`catalog_get_products`](/lokothodida/gs-catalog/wiki/API#getting-products) and [`catalog_get_product`](/lokothodida/gs-catalog/wiki/API#getting-an-individual-product) methods