Update DZNSegmentedControl.h

Exposed -setCount:forSegmentAtIndex:withGroupingSeparators: method. Inline documentation also included above method definition.
Update DZNSegmentedControl.h

Move grouping separator functionality to a property. Delete -setCount:forSegmentAtIndex:withGroupingSeparators: method definition.
Update DZNSegmentedControl.m

Change inside of if statement in the -countForSegmentAtIndex: method.
Update DZNSegmentedControl.m

Change -setCount:forSegmentAtIndex: method.
Update DZNSegmentedControl.m

Add -setShowsGroupingSeparators: method.
Add +defaultFormatter class method.
Use [[self class] defaultFormatter]
Merge pull request #18 from ndmeiri/master

Add functionality to add grouping separators to the counts of each segment.