mysqld_safe script did not heed MySQL specific environment variable
$UMASK, leading to divergent behavior between mysqld and mysqld_safe.

Patch adds an approximation of mysqld's behavior to mysqld_safe,
within the bounds dictated by attempt to have mysqld_safe run on
even the most basic of shells (proper '70s sh, not just bash
with a fancy symlink).

Patch also adds approximation of said behavior to mysqld_multi
(in perl).

(backport)

manual merge