CLIENT_LIBS in mysql_config as CLIENT_LIBS point to builddir when
we use the bundled zlib.


acinclude.m4:
  Extend MYSQL_CHECK_ZLIB_WITH_COMPRESS m4 macro to substitute ZLIB_DEPS -
  this is a special version of ZLIB_LIBS to use in mysql_config
configure.in:
  Remove NON_THREADED_CLIENT_LIBS which weren't really 
  NON_THREADED_CLIENT_LIBS and use NON_THREADED_LIBS instead.
  AC_SUBST NON_THREADED_LIBS and STATIC_NSS_FLAGS as they're now
  needed inside mysql_config.sh
scripts/Makefile.am:
  Add STATIC_NSS_FLAGS, NON_THREADED_LIBS and ZLIB_DEPS to sed 
  substitution list.
scripts/mysql_config.sh:
  We can't use CLIENT_LIBS as in case when we use the bundled zlib
  it has a reference to $(top_builddir)/zlib.
  libs and libs_r now need to be specified explicitly.
zlib/Makefile.am:
  Install libz.la in case it's used by MySQL: this way we guarantee
  that paths printed by mysql_config are valid in all cases.