Change entire structure of the 'Overview' window.

I have made the main OverviewPanel class easier to follow in that the four quadrants are now separated into four separate classes. 'StatisticsPane' 'SubmitPane' 'RequirementsPane' and 'AllEstimatesPane'
Change entire structure of the 'Overview' window

I have made the main OverviewPanel class easier to follow in that the four quadrants are now separated into four separated classes. 'StatisticsPane' 'SubmitPane' 'RequirementsPane' and 'AllEstimatesPane'
Added header comments to each of the class files
Merge pull request #113 from sfmailand/re-organization

Re organization
Tested by: Alec Thompson