There are various bits of cruft that have built up around our file accesses. This patch
cleans some of them up, specifically:
* Remove pointless "from __builtin__ import file"
* Use open(), not file()
* Wrap file usage in a with container to ensure files are closed
* Add missing .close() calls in some cases
(From OE-Core rev: a43e0a8ecd0441131e929daf998c3cd454d9c8f3)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
566628d8cd