Close tab on save

retrieve on save
remove redundant update()
run network tasks in a background thread
make retrieve call static
Added date & time picker

Date picker added to select due date to the nearest minute. If no date
is selected, gives null.
included swingx jar
Merge pull request #29 from dbeckwith/datepicker

Added date & time picker
Merge branch 'team9dev' into feature-emailnotification