Added support for auth plugins.

httpie/plugins/manager.py

@@ -0,0 +1,35 @@
+from pkg_resources import iter_entry_points
+
+
+ENTRY_POINT_NAMES = [
+    'httpie.plugins.auth.v1'
+]
+
+
+class PluginManager(object):
+
+    def __init__(self):
+        self._plugins = []
+
+    def __iter__(self):
+        return iter(self._plugins)
+
+    def register(self, plugin):
+        self._plugins.append(plugin)
+
+    def get_auth_plugins(self):
+        return list(self._plugins)
+
+    def get_auth_plugin_mapping(self):
+        return dict((plugin.auth_type, plugin) for plugin in self)
+
+    def get_auth_plugin(self, auth_type):
+        return self.get_auth_plugin_mapping()[auth_type]
+
+    def load_installed_plugins(self):
+
+        for entry_point_name in ENTRY_POINT_NAMES:
+            for entry_point in iter_entry_points(entry_point_name):
+                plugin = entry_point.load()
+                plugin.package_name = entry_point.dist.key
+                self.register(entry_point.load())