watch mode

[yoshuawuyts]

Reopening this as a follow up to #21.

Currently watchify kinda works with sheetify - since only new .js files are recompiled by browserify, just recreating new files from these events will cause incomplete files on recreation.

Maybe it's what #21 suggested, but I think the solution to this might be to send the stream in opts.out a "file" event so that it knows which are the new files, and which should be cached. I don't know how this would work on the cli tho in conjunction to watchify - should we perhaps have plugins such as browserify to make this work? I'm not sure, hah.

Thanks!

[yoshuawuyts]

This was fixed in v5 by relying on watchify to reload chunks, and only externalize the CSS once the bundle is done. https://github.com/stackcss/css-extract

[yoshuawuyts]

reopening because of #69