Makefile: convert check-auto-deps target into 'setup.py check_auto_deps'

Makefile

@@ -118,7 +118,7 @@ signal-error-deps:
 	exit 1
 
 check-auto-deps:
-	@$(PP) $(PYTHON) -c 'import _auto_deps ; _auto_deps.require_auto_deps()' || $(MAKE) signal-error-deps
+	$(PYTHON) setup.py -q check_auto_deps || $(MAKE) signal-error-deps
 
 .checked-deps:
 	$(MAKE) check-auto-deps

setup.py

@@ -238,6 +238,17 @@ class ShowPythonPath(Command):
         # Find a way to do this all the time.
         print "PYTHONPATH=%s" % os.environ["PYTHONPATH"]
 
+class CheckAutoDeps(Command):
+    user_options = []
+    def initialize_options(self):
+        pass
+    def finalize_options(self):
+        pass
+    def run(self):
+        import _auto_deps
+        _auto_deps.require_auto_deps()
+
+
 class BuildTahoe(Command):
     user_options = []
     def initialize_options(self):
@@ -374,6 +385,7 @@ setup(name='allmydata-tahoe',
       license='GNU GPL',
       cmdclass={"show_supportlib": ShowSupportLib,
                 "show_pythonpath": ShowPythonPath,
+                "check_auto_deps": CheckAutoDeps,
                 "build_tahoe": BuildTahoe,
                 "trial": Trial,
                 "sdist": MySdist,