Reformatting
Get rid of somewhat unnecessary popup in config screen
Reduce access based on actual need.

Also Get rid of an unused parameter.
Add (dummy) checkout provider stub for P4
Improve tracking of local file status
Refactor P4Wrapper API so that it is more consistent.

Move some changelist-related methods from P4Changelists into P4Wrapper
in anticipation of upcoming changes.
Use List where possible
Use List where possible
Add support for reverting files from the VCS "Changes" view
Add some rudimentary support for changelist creation, stubs for P4 submit
Add rudimentary support for P4 history provider
Support rollback through the VCS interface and add some stubs for P4 checkin, checkout, and history.