tkgui.py: tkinter stub
cli: new `start` function that all interfaces will have
main: include options to lauch tkinter gui
tkgui: testing the menu
move cli to subdir
gtk instead of tkinter. pseudo main menu. spacing is ... odd
cli/help.py: stub help module
cli/cli: import and use new help module
main: hide gtk gui for now
functions: include total service cost in get_summary results
cli: on `query` check if element is a date, rather than equals `date`
cli: fix call to edit vehicle, forgot to pass title
cli: more comprehensive summary, show total fuel/service/outright costs
functions: on `update_fuel` reverse calculate cost or ppl if possible
functions: on `get_summary`, provide running/total and costs per mile
cli: on `choose_fuel`, show costs. on summary use new values