Add a single command that will be used to construct the 'p4' command
Add a single command that will be used to construct the 'p4' command

Rather than having three locations where the 'p4' command is built up,
 refactor this into the one place. This will, eventually, allow us to
 have one place where we modify the evironment or pass extra
 command-line options to the 'p4' binary.

Signed-off-by: Anand Kumria <745d14a6451adc01f540e87d01c710e72d7f88b4@progsoc.org>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git