deploy-ng: Add bdist_panda3d command to create archives for each built platform

Linux platforms use tar.gz and everything else (Windows, macOS) uses
zip. Later we will want to add an option to control this. Also,
bdist_panda3d currently auto-runs build. We will want an option to skip
this build step for debug/testing purposes.

direct/src/showutil/dist.py

@@ -108,8 +108,40 @@ class build(distutils.command.build.build):
                 distutils.file_util.copy_file(src, dst)
 
 
+class bdist_panda3d(distutils.core.Command):
+    user_options = []
+
+    def initialize_options(self):
+        pass
+
+    def finalize_options(self):
+        pass
+
+    def run(self):
+        platforms = [p3d.PandaSystem.get_platform()]
+        build_base = os.path.join(os.getcwd(), 'build')
+
+        self.run_command("build")
+        os.chdir(build_base)
+
+        for platform in platforms:
+            build_dir = os.path.join(build_base, platform)
+            base_dir = self.distribution.get_name()
+            temp_dir = os.path.join(build_base, base_dir)
+            archive_format = 'gztar' if platform.startswith('linux') else 'zip'
+            basename = '{}_{}'.format(self.distribution.get_fullname(), platform)
+
+            if (os.path.exists(temp_dir)):
+                distutils.dir_util.remove_tree(temp_dir)
+            distutils.dir_util.copy_tree(build_dir, temp_dir)
+
+            distutils.archive_util.make_archive(basename, archive_format, root_dir=build_base, base_dir=base_dir)
+
+            distutils.dir_util.remove_tree(temp_dir)
+
 def setup(**attrs):
     attrs.setdefault("distclass", Distribution)
     commandClasses = attrs.setdefault("cmdclass", {})
     commandClasses['build'] = build
+    commandClasses['bdist_panda3d'] = bdist_panda3d
     distutils.core.setup(**attrs)