Switch POM to use p4java 2013.2.894409-SNAPSHOT.

- p4java bug fix for spaces in workspace Root
Fix: no changes after a successful build.

avoid a null pointer if there are no changes after a successful build.
Add support for Environment variables.

Includes cleanup of Perforce exception reporting for Connections and
Workspaces.
File limit on detailed change set view.

Limited the list of files shown in a change to 50 for changes
contributing to a build.
Clear Workspace environment between builds.
Set environment P4_CHANGELIST

Using the value from TagAction set after a build.
Use `-p` (not `-k`) for bypass have.
Merge remote-tracking branch 'upstream/master'

Pull fixes from dev 'p4-paul'