Implement ZipWriter for quickly writing ZipFiles.

The ZipWriter implementation exposes a stateful interface that allows
bytes of data to be streamed in as they arrive. ZipEntries can be
compressed and/or aligned on a 32-bit boundary for mmapping at runtime.

Bug:22489826
Change-Id: Ifdabcde3ea5747dd4bcf0c4ac0eb5c394277443c