Updated DataSourceAdapters for sectioned arrays.
* Item access in ArrayDataSourceAdapter to handled the possibility of sectioned arrays
* Updating/Manipulating items now plays nicer with sectioned arrays
* Helper functions in base data source for generating arrays of indexpaths no longer assume 0 as the section
Merge branch 'master' into dev-fix
updating example proj
Merge pull request #2 from urbn/dev-fix

Updated DataSourceAdapters for sectioned arrays.