fixed class/object labels to be centered
added some comments for clarity
Merge remote-tracking branch 'origin'
Merge remote-tracking branch 'origin'
added method to draw arrows, not in use yet
updated appropriate values to floats
fixed some potential float/int errors, moved some variables to be instance variables
created a SequenceDiagramAction struct
Friday, February 8th, 2013, at 3:18 P.M:

1. Comment out all codes involving MediatingController
since invocation queue was removed, commented out UMLView.m
Merge remote-tracking branch 'Sequence-Diagram-GitHub/Nick'
Friday, February 8th, 2013, at 3:23 P.M:

1. Make some changes to notification mechanism
added code to account for the fact that there might be no parameters for a SequenceDiagramAction
syntax error noticed before push
Friday, February 8th, 2013, at 3:53 P.M:

1. Finish implement the new notification mechanism
Merge remote-tracking branch 'Sequence-Diagram-GitHub/Nick'
removed more references to invocation queue
Merge remote-tracking branch 'Sequence-Diagram-GitHub/Nick'
Friday, February 8th, 2013, at 4:01 P.M:

1. Change the code a bit so that the info dictionary gets the right values