Started the AddActivty class, made the con variable in the deposit class
private
Added and configured the screen to add an activity, made the
functionality to the button and included the error label.
AddActivity class nearly complete, only some rules need to be
implemented like the 150 char max length of the a_name
Finalized the class to add an activity, it now checks for certain
criteria (length of name, correct order of dates etc)
Merge pull request #4 from Ylvakiller/AddActivity

Merging AddActivity to the master branch