merge: use merge.clean_update() when applicable
We have had this higher-level function (higher than `merge.update()`,
that is) for a while. Let's simply some callers by using it. I don't
know why I didn't do this when I introduced the function.
After this patch, there are no remaining callers that call
`hg.updaterepo()` with `overwrite=True`. We'll clean that up soon.
Differential Revision: https://phab.mercurial-scm.org/D9063
{
// 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)
}