Major improvements, deduplication and simplification in over.app.

- over.app.ConfigFile can create empty config files and read all options from them
- over.callback was created to hold commandline parser callbacks
- over.app.Option.is_boolean hint added
- major improvements and increased robustness of over.app.Main command line parser

over/callback.py

@@ -0,0 +1,36 @@
+#! /usr/bin/env python3
+# encoding: utf-8
+
+# --------------------------------------------------
+
+def boolean(arg):
+	"""
+	Converts
+	- "True", "true" or "1" ⇒ True
+	- "False", "false" or "0" ⇒ False
+	
+	@while converting argument to bool
+	"""
+	
+	if arg in (True, "True", "true", "1"):
+		return True
+	elif arg in (False, "False", "false", "0"):
+		return False
+	else:
+		raise ValueError(arg)
+
+def booleans(*args):
+	"""
+	Converts each
+	- "True", "true" or "1" ⇒ True
+	- "False", "false" or "0" ⇒ False
+	
+	@while converting arguments to bools
+	"""
+	
+	out = []
+	
+	for arg in args:
+		out.append(boolean(arg))
+	
+	return out