Do not override Powerline.setup(), use .do_setup() for this

Same reason as for `.__init__()` which was replaced by `.init()`

powerline/__init__.py

@@ -744,11 +744,21 @@ class Powerline(object):
 	def setup(self, *args, **kwargs):
 		'''Setup the environment to use powerline.
 
-		To be overridden by subclasses, this one only saves args and kwargs and 
-		unsets shutdown_event.
+		Must not be overridden by subclasses. This one only saves setup 
+		arguments for :py:meth:`reload` method and calls :py:meth:`do_setup`.
 		'''
 		self.shutdown_event.clear()
 		self.setup_args = (args, kwargs)
+		self.do_setup(*args, **kwargs)
+
+	@staticmethod
+	def do_setup():
+		'''Function that does initialization
+
+		Should be overridden by subclasses. May accept any number of regular or 
+		keyword arguments.
+		'''
+		pass
 
 	def reload(self):
 		'''Reload powerline after update.

powerline/ipython.py

@@ -56,6 +56,5 @@ class IpythonPowerline(Powerline):
 			mergedicts(r, self.theme_overrides[name])
 		return r
 
-	def setup(self, attr, obj):
+	def do_setup(self, attr, obj):
 		setattr(obj, attr, self)
-		super(IpythonPowerline, self).setup(attr, obj)

powerline/shell.py

@@ -43,9 +43,8 @@ class ShellPowerline(Powerline):
 			for key, val in local_themes.items()
 		))
 
-	def setup(self, obj):
+	def do_setup(self, obj):
 		obj.powerline = self
-		super(ShellPowerline, self).setup(obj)
 
 
 def get_argparser(parser=None, *args, **kwargs):

powerline/vim.py

@@ -110,8 +110,7 @@ class VimPowerline(Powerline):
 		except KeyError:
 			return super(VimPowerline, self).get_config_paths()
 
-	def setup(self, pyeval=None, pycmd=None, can_replace_pyeval=True):
-		super(VimPowerline, self).setup()
+	def do_setup(self, pyeval=None, pycmd=None, can_replace_pyeval=True):
 		import __main__
 		if not pyeval:
 			pyeval = 'pyeval' if sys.version_info < (3,) else 'py3eval'