bitbake: bitbake: Convert to python 3

Various misc changes to convert bitbake to python3 which don't warrant
separation into separate commits.

(Bitbake rev: d0f904d407f57998419bd9c305ce53e5eaa36b24)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/bin/bitbake

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ex:ts=4:sw=4:sts=4:et
 # -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
 #
@@ -35,6 +35,9 @@ except RuntimeError as exc:
 from bb import cookerdata
 from bb.main import bitbake_main, BitBakeConfigParameters, BBMainException
 
+if sys.getfilesystemencoding() != "utf-8":
+    sys.exit("Please use a locale setting which supports utf-8.\nPython can't change the filesystem locale after loading so we need a utf-8 when python starts or things won't work.")
+
 __version__ = "1.31.0"
 
 if __name__ == "__main__":