Exchange UltiSnips with old snipmate.

I'm not very heavy user of snippets. UltiSnips lately dropped support
for python2, yet I'm using some machines with old OSes, which complain a
lot during boostrapping my vimrc, so I was started to look for a simpler
replacement. Finally decided on a (slightly modified) original snipmate.

snippets/python.snippets

@@ -0,0 +1,35 @@
+snippet #!
+	#!/usr/bin/env python
+
+snippet #!2
+	#!/usr/bin/env python2
+	# coding: utf-8
+
+snippet utf
+	# coding: utf-8
+
+snippet #!3
+	#!/usr/bin/env python3
+
+snippet dbg Python Debugger abbrv
+	__import__('pdb').set_trace()
+
+snippet ipdb ipdb abbrv
+	__import__('ipdb').set_trace()
+
+snippet rpdb remote_pdb debbuger
+	__import__('remote_pdb').set_trace()
+
+snippet msg Tk graphical message
+	from Tkinter import Tk
+	import ttk
+	import tkMessageBox
+	window = Tk()
+	window.wm_withdraw()  # make window invisible. we only want message boxes
+	ttk.Style().theme_use('clam')
+	tkMessageBox.showinfo(title="${1:title}",
+						  message="${2:msg}",
+						  parent=window)
+
+snippet _ Dunder completion
+	__${1:init}__$0