Fill in all packages without README.md files with a short
README.md mentioning that this is an internal Meteor package.
Break up the top paragraph of a couple of existing README.md
files to be proper long description.
There is more work to do here, involving line wrapping and the like.
@export is now an error in test slices.
This is preparation for ensuring that any slice with exports has at least
"Package.foo = {}"; without this commit, both the use and test slice would (with
that change) try to overwrite Package.foo.
Remove the attempt to allow @export in 'use strict' CoffeeScript files:
ECMAScript 'use strict' is fundamentally incompatible with our implementation of
exports, and it was probably a bug that this used to work at all.
