Improve IBM Z patch
Most of this is minor changes to use GNU style and C99 constructs.
* NEWS: Mention IBM Z.
* bootstrap.conf (gnulib_modules): Add stdalign.
* dfltcc.c: Include stdalign.h, stdbool.h.
(union aligned_dfltcc_qaf_param, union aligned_dfltcc_param_v0):
New types, used for C11-style alignment. All uses changed.
(init_param):
* gzip.c (BUFFER_ALIGNED): New macro.
(inbuf, outbuf, window): Use it, so buffers are aligned everywhere.
* gzip.h (INBUFSIZ, OUTBUFSIZE): Use big buffers everywhere,
unless SMALL_MEM.
* zip.c (SLOW, FAST): Now enums since they need not be macros: