added the budgetSettings activity
added the basic layout for the budgetSettings activity
implemented the basic look of the budgetSettingsActivity
implemented the AlertDialogue for setting the monthly budget
budgetSettingsActivity recounts the daily budget for the month
limited the amount of decimal places to 2 for edittexts
reorganized the packages into a more logical view
refactored xml file names to more appropriate and logical
modification of the decimal digits helper class

I modified the decimal digits helper class regex pattern
so that it would not be possible to start of the number with
a zero like 012345. Made a new DecimalDigits constructor that
doesn't take any arguments, as that was unneccessary. Fixed
the calls to the helper class apropriately. Also
I made it possible to start of a number with a zero, but it should
be followed by a "." in order to meet the regex pattern.
modified the decimalDigits regex

modified the regex in the decimalDigits class
to handle the case of user being able to enter "."
right away, as some users prefer to start their
input like that
added a check for input not allowing a "."

I implemented the isValidInput method in the DecimalDigits
class, because my regex expression allows the user to enter
just a "." by itself, therefore this methods checks whether
the user put in a period by itself, and sets the error
on the input edittext. This check is implemented both for the
input in the addExpense class and budgetSetting class alertDialog.
modified isValidInput method for validatin the "."

Changed the isValidInput method for validating a single "."
character. Corrected the conditional statement for
setting an error.
added another check to DecimalDigits isValidInput method

Removed the formatting for the textview in the budgetSettingsActivity
once the user sets the budget. Instead I implemented a check that won't
let the user close the dialog if he leaves a trailing dot in his input.
Also added some javadocs and comments for budgetSettingsAcitivty and
DecimalDigits class for easier code review and orientation.