This fixes remaining issues that prevented use of package
to encode manifest for packaging correctly.
* Chunk headers are now encoded based on content
* Fixes for namespace and value fields
* Improved sorting based on native aapt output
Change-Id: Ic63046973a7b0431533463ed4dd2de50f1d73191
Reviewed-on: https://go-review.googlesource.com/19224
Reviewed-by: David Crawshaw <crawshaw@golang.org>