This is the newest version that doesn't use let (which we don't support).

Also, change the argument processing the use -L: to prepend the load path
and -l: to append.

This update required disabling support for:
Arrow functions (the => 'operator')
Mega strings (The ` and ${} things that are SO AWESOME)
And the following newer standard objects:
DataView, Generator, GeneratorFunction, Intl, Map, Promise, Reflect, Set,
Symbol, System, WeakMap, WeakSet

This makes it an error for the same file to be load()ed multiple times
without require.pl being used after the first time.

filter unwanted properties" warnings by default.  This is more for when
you're worried that your object may be exitended... a rare situation in
Synchronet JavaScript.

immediately within another function"

Add a -report option which gives a list of defined globals as well as a list
if functions which shows what variables are used/unused.

noextracommas) and set up the defaults to ignore them.

The only questionable one is the poorrelations which suggests using === and
!== when comparing with the constants 0, '', true, false, undefined, and null

skips a file after it has been load()ed once.

command line.

    if(something)
        do_something();

inside a comment.

Synchronet JS scripts.