Minor fixes in icon resolution

MS tiles for Win 8.1 and 10 match recommendations (see https://msdn.microsoft.com/library/dn455106(v=vs.85).aspx)

Add command-line access

Fix multi source config

Coast was being set twice and windows was not set at all.

Fix bug where, if you weren't generating all icon formats, you couldn't
use a multiple sources configuration.

checks for 2xx codes and sends original error message

monkeypatch unzip.Parse.emit() to emit single 'end'

Add cli access via minimist which takes argument flags and passes them
in as the config object.

unzip is not so well-behaved. It typically emits a 'close' event
when it's done, but there are reports that sometimes it doesn't,
and that sometimes it emits 'end' instead. Monkeypatch emit() so
that it emits just one 'end' event from any combination of 'close'
and 'end' events.

getConfig() now handles missing options.files

Expose stream and config

Unity