git-p4: remove "debug" verb

The git-p4 "debug" verb is described as "A tool to debug the output of
p4 -G".

The verb is not documented in any detail, but implements a function
which executes an arbitrary p4 command with the -G flag, which causes
perforce to format all output as marshalled Python dictionary objects.

The verb was implemented early in the history of git-p4, and may once
have served a useful purpose to the authors in the early stages of
development. However, the "debug" verb is no longer being used by the
current developers (and users) of git-p4, and whatever purpose the verb
previously offered is easily replaced by invoking p4 directly.

This patch therefore removes the verb from git-p4.

Signed-off-by: Joel Holdsworth <jholdsworth@nvidia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-p4.py

@@ -1532,21 +1532,6 @@ class P4UserMap:
         except IOError:
             self.getUserMapFromPerforceServer()
 
-class P4Debug(Command):
-    def __init__(self):
-        Command.__init__(self)
-        self.options = []
-        self.description = "A tool to debug the output of p4 -G."
-        self.needsGit = False
-
-    def run(self, args):
-        j = 0
-        for output in p4CmdList(args):
-            print('Element: %d' % j)
-            j += 1
-            print(output)
-        return True
-
 class P4RollBack(Command):
     def __init__(self):
         Command.__init__(self)
@@ -4363,7 +4348,6 @@ def printUsage(commands):
     print("")
 
 commands = {
-    "debug" : P4Debug,
     "submit" : P4Submit,
     "commit" : P4Submit,
     "sync" : P4Sync,