Unify headers and use logging in schematics

- Schematics: Import and use logging
 - Demos & test : Unify headers

src/demo_clean_unknown.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python3.4
+#!/usr/bin/env python3
 # -*- encoding: utf-8 -*-
 ############################
 ## Demo of Python-Minetest :

src/demo_schematic_manipulation.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python3.4
+#!/usr/bin/env python3
 # -*- encoding: utf-8 -*-
 ############################
 ## Demo of Python-Minetest :
@@ -41,6 +41,9 @@ if __name__ == "__main__":
 		db.set_maxcachesize(40)
 		print("Reading schematic...")
 		schem = minetest.schematics.Schematic(schfile)
+		if not schem:
+			print("No schematic imported. Aborted.")
+
 		print("Importing schematic..")
 		db.import_schematic(pos_import, schem, stage_save=True)
 		print("Saving...")

src/logger.py

@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # -*- encoding: UTF-8 -*-
 ##########################
 ## Logger for python-minetest

src/schematics.py

@@ -8,6 +8,7 @@
 
 from nodes import Node
 from utils import readU16, readU8, readU32, writeU16, writeU8, writeU32
+from logger import logger
 
 import zlib
 from io import BytesIO
@@ -68,7 +69,7 @@ class Schematic:
 		try:
 			assert(data.read(4) == b"MTSM")
 		except AssertionError:
-			print("ERROR: {0} couldn't load schematic from data : invalid signature".format(self))
+			logger.error("{0} : Couldn't load schematic from data : invalid signature".format(self))
 			return
 
 		self.version = readU16(data)
@@ -144,7 +145,7 @@ class Schematic:
 		try:
 			ifile = open(filename, "rb")
 		except Exception as err:
-			print("ERROR: {0} couldn't open file {1} : {2}".format(self, filename, err))
+			logger.error("{0} : Couldn't open file {1} : {2}".format(self, filename, err))
 			return
 
 		self.load(ifile)
@@ -153,7 +154,7 @@ class Schematic:
 		try:
 			ofile = open(filename, "wb")
 		except Exception as err:
-			print("ERROR: {0} couldn't open file {1} : {2}".format(self, filename, err))
+			logger.error("{0} : Couldn't open file {1} : {2}".format(self, filename, err))
 			return
 
 		ofile.write(self.export().read())

src/test.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python3.4
+#!/usr/bin/env python3
 # -*- encoding: utf-8 -*-
 ############################
 ## Tests ran for Python-MT