[PATCH 1 of 5] obsolete: add isenabled function for option checking

[Durham Goode]

On 10/14/14 2:51 PM, Durham Goode wrote:
> # HG changeset patch
> # User Durham Goode <durham at fb.com>
> # Date 1413317855 25200
> #      Tue Oct 14 13:17:35 2014 -0700
> # Node ID a22ff14b5ff64123d37e1fc42cad86cf76a4c3b1
> # Parent  75d0edb68b417964110e3fcd69187c867f31a119
> obsolete: add isenabled function for option checking
This series just introduces the options.  A future series will update 
the tests and remove the old obsolete._enabled flag.