selftest.createApp shouldn't copy .meteor/local

just like 'meteor create' / 'meteor create --example'

it was breaking if you had a .meteor/local since it could contain a
node_modules which was a symlink to a directory, and cp_r doesn't
support copying directory symlinks
stop using cp_r for non-recursive publishs source

This lets us rip out the weird 'include' argument and go back to just
stat'ing things instead of lstat'ing.

While we're at it, be more streamy when doing these copies.
use streamy copy in builder too