moved dispatch display/rigging to render()
Revert "moved dispatch display/rigging to render()"

This reverts commit 41d702c278b0f647f4e09a85a5e8187c658d1664.
Dispatch constructor set to use nonexistant Category class
list items rendering under category headings
category names in info windows
alphabetized categories
default category title for dispatches with blank categories
category is hidden when all its dispatches are hidden