Reorganize strings.xml
Added dialog for selecting group items by.
Use v13 fragments instead of v4
Minor formatting
Added ability to group items. (Still a work in progress)
The different groups are represented as different tabs. Currently, only
works for assigned to, workflow steps, and priorities.

Works that needs to be done: 
-Group by status for Help Desk screen and group by item type for All
Types screen
-Disable groups / Group by None
-Only display the workflow steps that belongs to a single workflow
chosen by the user
-Reorder groups is desecnding order
-Add a tab for all items
-Give options to filter out empty groups
-Remember the last selected tab when switching between item types
-bug fixes/opmizations