Also did the following -
1. Changed get_grade_items() so it takes a course parameter.
2. Renamed get_grade() and get_mod_grade() and changed functionality
slightly to use newly introduced class.
3. Do not return a date graded value if there is no grade.
4. Added course grade date as an option to the date element.
5. Fix inconsistency between number of decimals showing for a grade
between the drag and drop interface and the PDF.
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.
