LDEV-4273: Initial check of Assessment's use of histogram. Added a simple summary table of results to the first worksheet in the spreadsheet export - grouping the overall marks received. Modified the SQL code used to do the Monitor screen paging as the CASE appears to be causing the marks to sort as if they were strings, rather than numbers.
LDEV-4271 Refactor Assessment code * use DTO instead of model classes for carrying interim information * split learning.jsp into two pages: actual learning.jsp where user enters his answers and results.jsp where we display results to him