bitbake: lib: Clean up various file access syntax

Python 3 is stricter about how files are accessed. Specficially:

 * Use open(), not file()
 * Use binary mode for binary files (when checksumming)
 * Use with statements to ensure files get closed
 * Add missing file close statements

(Bitbake rev: 9f08b901375ba640f47596f1bcf43f98a931550f)

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

bitbake/lib/bb/parse/parse_py/ConfHandler.py

@@ -145,6 +145,8 @@ def handle(fn, data, include):
     if oldfile:
         data.setVar('FILE', oldfile)
 
+    f.close()
+
     for f in confFilters:
         f(fn, data)