Remove + 1 in month variables, delete expenselist

All month variables that were set before were added 1
to the them so that the text views were given the right
value from the list of months. This is no longer necessary.

- remove all the +1 in the month variables where it is not
needed anymore
- change the group header in expandablelistactivity to
month / day / year
- redirect the user to the expandableExpenseActivity instead
of expenselist