Add bmcweb target to S2600Wf

This changeset replaces phosphor rest with bmcweb for the s2600wf
target.  bmcweb has several advantages over phosphor-rest.
1. Written in C++.
2. Supports Asyncronous transactions
3. Authentication backed by PAM
4. SSL key generation, and modern SSL cipher suites
See the application readme for more

To enable bmcweb, this patchset also:
1. Revs libtinyxml to the latest version 6.0.0 from the existing 3.0.0
2. Adds the boost-dbus recipe, to allow bmcweb to build.  Bmcweb is a
header only dbus library.

Change-Id: I5b90427977709127c09fedcfc4bcb713908d356f
Signed-off-by: Ed Tanous <ed.tanous@intel.com>
diff --git a/meta-intel/meta-common/recipes-intel/libtinyxml2/libtinyxml2_%.bbappend b/meta-intel/meta-common/recipes-intel/libtinyxml2/libtinyxml2_%.bbappend
new file mode 100644
index 0000000..60cfe5e
--- /dev/null
+++ b/meta-intel/meta-common/recipes-intel/libtinyxml2/libtinyxml2_%.bbappend
@@ -0,0 +1,3 @@
+# update libtinyxml2 to version 6.0.0
+SRCREV = "8c8293ba8969a46947606a93ff0cb5a083aab47a"
+FILES_${PN}-dev += "${libdir}/cmake/tinyxml2/*"