Handle ints passed to bool_from_string

[Rick Harris]

Nova and Oslo have two slightly different versions of `bool_from_string`.

For Nova, the int 1 and int 0 become True and False respectively.

For Oslo, both return False. (There are no tests defining this behavior in Oslo, so the official behavior is undefined).

Admittedly it's subjective, but Nova's behavior feels more correct here.

(Aside: Nova also has the behavior that string '2' is True whereas in Oslo it's False.

Again, Nova's behavior feels more correct, but given that, unlike the int case, Oslo has tests which *define* this as correct, it's probably better to hold onto the existing behavior.)

So the proposal here is to:

Teach Oslo's bool_from_string how to deal with ints like Nova's version.
Hold onto Oslo's dubious way of dealing with numbers as strings.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/28856

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/28856
Committed: http://github.com/openstack/oslo-incubator/commit/d9b0719f02433b243a20fe705af4799c619f4e28
Submitter: Jenkins
Branch: master

commit d9b0719f02433b243a20fe705af4799c619f4e28
Author: Rick Harris <email address hidden>
Date: Fri May 10 23:07:27 2013 +0000

    Handle ints passed to `boolean_from_string`

    The existing code would return True for '1' but False for int(1),
    unlike Nova's version which would return True for both inputs.

    Nova's version feels safer (i.e. it will do the most-likely-correct
    thing if an int is passed in), so this patch changes
    Openstack-Common's version to match.

    Note that this patch does not make Openstack-Common's
    `boolean_from_string` match Nova's `bool_from_string` exactly though.
    Nova's version would return True for both '42' and 42, while
    Openstack-Common's returns False. Though Nova's version, again, seems
    safer, the presence of unit-tests in Openstack-Common asserting the
    defined-correctness of this behavior makes me reluctant to change it.

    Fixes bug 1178760

    Change-Id: I8b2a31c4852884187bcbda3a4e78c8513b1bb8c8