add callback functionality to grid selection to execute logic after selection changes (either single selection, or select all)
tab -> spaces, cleanup indentation
add unit tests to exercise afterSelect{All,Row}
Changed context and added deselection callbacks
Reformat whitespaces
preserving the signature
Changed the callback positions
Removed deselect callbacks as they can be determined using the status
Modify tests as per the changes made
Merge pull request #251 from PrimeRevenue/feature/jqgrid_selection_callbacks

Feature/jqgrid selection callbacks