narrow: move manifestlog overrides to core
With this and the previous patch, I couldn't measure any significant
difference from `hg files -r .` in a FireFox repo with 65k files. I
tried with both a flat-manifest and a tree-manifest version of
it. Neither had the narrow extension enabled.
Differential Revision: https://phab.mercurial-scm.org/D3046
{
// 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)
}