.jshintrc

scmutil: speed up relativization of paths when it's a no-op

Running commands from the root is commmon, in particular for
automation. Running `hg files > /tmp/a` from the root of
mozilla-central on linux:

before:
real	0m1,510s
user	0m1,387s
sys	0m0,090s

after:
real	0m1,266s
user	0m1,165s
sys	0m0,073s

(there are 280k paths, so this was costing ~1us per path somehow)

Differential Revision: https://phab.mercurial-scm.org/D8585

{
    // 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)
}