.jshintrc

typing: add type hints to argument checking functions in cmdutil

These might be surprising, since they can take strings instead of bytes.  The
way `AnyStr` works is that it must be all bytes or all str for any given
invocation.

The wildcard here will be the `opts` that get passed in- if the type is unknown
and defaults to `Any`, there's no enforcement that the dict key type matches the
additional args.  But a lot of uses should be using `**opts` from the command
method, which has a str key.  The uses of these methods in this module are now
typed because their internals force a specific type, and it can't just be
inferred from the caller.

{
    // 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)
}