discovery: use a lower level but faster way to retrieve parents
We already know that no revision in the undecided set are filtered, so we can
skip multiple checks and directly access lower level data.
In a private pathological case, this improves the timing from about 70 seconds
to about 50 seconds. There are other actions to be taken to improve that case,
however this gives an idea of the general overhead.
{
// Enforcing
"eqeqeq" : true, // true: Require triple equals (===) for comparison
"forin" : true, // true: Require filtering for..in loops with obj.hasOwnProperty()
"freeze" : true, // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
"nonbsp" : true, // true: Prohibit "non-breaking whitespace" characters.
"undef" : true, // true: Require all non-global variables to be declared (prevents global leaks)
// Environments
"browser" : true // Web Browser (window, document, etc)
}