Because the async_status module will read from the same file that
the async_wrapper module is writing, it's possible that the file
may not be fully synced during a read, causing spurious failures.
Use a temp file to do an atomic operation on the file. We can't
use atomic_move() here as that doesn't work properly under async.
Also, let's not read concurrently from the same file the subprocess
is writing to. Instead, capture stdout/stderr via PIPE and write to
the file to avoid nasty races.
Prior to Python 2.5, SystemExit was a subclass of Exception.
In Py2.4, this is causing extra error output on valid sys.exit(0).
(Toshio) Call sys.exit from inside of the SystemExit exception handler so py2.4 and py2.5+ behaviour matches
* Fixing compile time errors irt a) exception handling for Python 3 in util, also: b) problem octal usage (fixed) and c) print json_dump -> print(json_dump(xyz) ... et al
* This code was not Python 2.4 compliant. Octal codes and exception handling is now working with Py 2.4, 2.6, & 3.5.
* Fixing formating (or rather reverting an non 2.4 compatible change). Works in compile & runtime checking.
* a) revert to use print sys.stderr not fail_json; b) fixed var name in exception
* Python 3 compatible print (print >>sys.stderr will generate a TypeError - now uses sys.stderr.write instead).
