Reduced the number of warnings and resolved some ToDos for ticket #601
Fixed many compiler errors for ticket #601
Backup commit for ticket #601
Deleted merged branch for ticket #612
merged branch for ticket #612
Added doxygen comments for the new TableColumn classes for ticket #601
Created initial version of table columns for ticket #601
improvements for better readibilty and simpler code. Referring to ticket #612
Created branch for ticket #601