Big redesign of flight time calculator and night time calculator.Added maintenance tab to flights submenu.Fixed problem in night calculator utility from previous change.I still have a todo list for the night calculator code, this refactor is the first step. A lot of of the code refactoring work will make it easier to maintain and enhance as time goes on. The core functionality and database hasn't changed, everything should work same as before but navigation and look and feel is slightly different.
