cosmetic: use a slightly more descriptive names
Move JS code for ports to their own module
Add -W flag
Add Native.Ports to prelude for user defined modules
Detect errors in port usage (i.e. too many or too few)
Filter out duplicate imports, generate code using new Native.Ports module
Take ports out of MetadataModule, where it is no longer needed
cosmetic: make a block of code more whitespace friendly