dhcp: update 4.4.1

dhcp: update 4.4.1

include several CVE fixes.
CVE: CVE-2018-5733
CVE: CVE-2018-5732

LIC_CHKSUM_FILE updated to SPFX format

https://kb.isc.org/article/AA-01571

remove several patches now included in update.
Shared libarary support is now enabled in configure+lt, use it
and revert to autotools-brokensep
Refresh patches

aligns support with bind 9.11.x

add libxml2 support to configure.ac+lt

[v2]
cleaned up do_configure per feedback
fix hard coded lib & include patch

Signed-off-by: Armin Kuster <akuster808@gmail.com>