Merge branch 'trac3576' Add PXE options

Add several options PXE uses, also add the OptionOpaqueDataTuples
class to provide support for the parameter list option.

Conflicts:
	ChangeLog

diff --cc ChangeLog
index 158636f0d6b12983cc7da5293d3662d4a5e7f107,dd3ef6cfb2f3466aa4886a6574f2f27e73483d23..d4fffd91d411bed8604b2733d313d12b964b2a28
--- 1/ChangeLog
--- 2/ChangeLog
+++ b/ChangeLog
@@@ -1,39 -1,11 +1,47 @@@
 -101x.   [func]                sar
++1018.   [func]                sar
+       Added support for several options for use by PXE.
+       From RFC4578 (for DHCPv4) these are: 93 - client-system,
+       94 - client-ndi, 97 - uuid-guid.
+       From RFC5970 (for DHCPv6) these are: 59 - bootfile-url,
+       60 - bootfile-param, 61 - client-arch-type, 62 - nii.
+       (trac #3576, git <TBD>)
+ 
 +1017. [func]          tmark
 +      Lease dump SQL logic, used by kea-admin, is now supplied via stored
 +      procedures rather than external text files.  Files of the form
 +      lease_dump_<version>.sh will no longer be installed under
 +      <prefix>/share/kea/scripts.
 +      (Trac #3916, git 09cdd86a5e284250d7657a93a36df2e2705947d2)
 +
 +1016. [bug]           fdupont
 +      Fixed problems when --enable-static-link is specified as a
 +      "configure" option. With this switch present, all Kea
 +      executables (servers, tools, unit tests, etc) are linked
 +      to the static (vs. shared) version of Kea libraries.
 +      However, note that they can still be linked to dynamic
 +      system libraries.
 +      (Trac #4004, git 760a343efbd241f5ed333cfff088124378f69115)
 +
 +1015. [func]          tomek
 +      Expired declined leases can now be reclaimed (returned to the
 +      available pool) after probation period elapses.
 +      (Trac #3984, #3976, git 32a8ec68e0e5ea93991915812158d7628d2b4709)
 +
 +1014. [func]          marcin
 +      Implemented lease4_expire and lease6_expire hooks in libdhcpsrv.
 +      (Trac #3972, git 8a8547aec1caf2a8d1c7ca206f68534f3c03f1d9)
 +
 +1013. [func]          marcin
 +      New mechanism for scheduling lease file cleanup is used in the
 +      DHCPv4 and DHCPv6 servers.
 +      (Trac #3971, git 431d515fc3d64aa82369c8eaf48d03339f12dc69)
 +
 +1012. [bug]           stephen
 +      Replace #include of message_dictionary.h in message_initializer.h
 +      with a declaration of the MessageDictionary class, avoing the need
 +      to include message_dictionary.h in the set of header files installed.
 +      (Trac #4046, git 9f1801b4326f62632a7c9f0aa939d58f120c10e8)
 +
  1011. [func]          fdupont
        Added definitions and tests for the options from secure DHCPv6.
        This protocol is still experimental. The option and other protocol

diff --cc src/lib/dhcp/tests/libdhcp++_unittest.cc
Simple merge