Upgrade the package to R55. Patches refreshed.

Added `-DMKSHRC_PATH=\"/etc/mkshrc\"` to `CPPFLAGS` to set the default
startup file during both login and nonlogin sessions, so that there is
no need to source `/etc/mkshrc` file manually.

In addition to the package upgrade, use PKG_HASH instead of
PKG_MD5SUM.

Reviewed-by: Thorsten Glaser <tg@mirbsd.org>
Signed-off-by: Alif M. Ahmad <alive4ever@live.com>