#21 Further cleanups
Retrieved Upcoming transactions first.

Want the message from normal transacts to be last.
#22 Added a PIN control
#22 Just a bit of cleanup
#22 Added a screen to login with the pin
#22 Reworked security so you can set a screen to need a pin

A password is only needed once per session, but a pin is required every
time you open the screen. If you haven't set a pin you will be prompted
for a password.
You can set a screen to be PasswordAndPin, which will use a password if
it hasn't been entered this session, after that first time it will ask
for the pin.