The table is now an instance of 'table_sql', not 'html_table'.
This made sorting easy to implement, with the added benefit
of taking advantage of the spout library for exporting data.
1) Every certificate is a template. Before a user would create a certificate then had
the option to save it as a template. This could potentially be chaotic with numerous
users creating templates, making the template system a mess. Now, rather than creating
a certificate first, then saving it as a template, you are always creating a template.
Each template is associated with a context, so depending on where you are creating it
the context is different. This means users in the CONTEXT_MODULE context are creating
a template specific to that module, where as a user creating a template in the
CONTEXT_SYSTEM context would be creating a general template that can be used by others.
This meant we can remove the 'customcert_template_*' db tables. Yay - no duplicated
tables.
2) Created new helper classes and moved functionality there.
3) Moved files to classes/ for autoloading.
4) General tidy up.
