Added Charts Tab, with a simple diagram to test.
Added needed library: androidplot-core-0.6.1.jar
Minor Bug Fixes.
Updated Social Tab.
Friend requests are now displayed, and can be accepted or declined.

Every interaction with AppFacade now runs via a AsyncTask.
Merge pull request #45 from XiDevelopment/social-tab

Social tab
Added images for Social and Charts Tab.
Every fragment_social_*.xml now uses dimens.xml.
Added progress display to social tab.
Change in BikeChallenge.iml.
Added a task and progress indicator to charts tab.
Added a refresh menu item to charts and social tab.
Typos in social tab.
Added swipe down refresh to charts and social tab.
Social tab strings.
Updated Model files.
Charts tab now displays a statistic object correctly.
Merge pull request #46 from XiDevelopment/charts-tab

Charts and Social Tab update.