Log message:
Make -Wunused-function non-fatal for clang.

Log message:
Fix header guard.

Log message:
Explain xen version differences.

There are 5 versions of xen in pkgsrc, which is confusing.  Explain in
DESCR which version is in which package (xenkernel3 contains 3.1), and
which versions support PCI passthrough (only 3.1).  Explain which
versions support non-PAE (3.1) and PAE (3.3, 4.1, 4.2), because the
HOWTO is out of date and it's easy to end up with a non-working system
on a 3.1 to 3.3 update.  Cuation that 2.0 is beyond crufty.

This is a DESCR-only change (with PKGREVISION++ of course).

(ok during freeze agc@)

Log message:
Partially back out change to PYTHON_FOR_BUILD_ONLY.

This broke packages that needed a target Python at build-time.
Instead, change it from defined/undefined to yes/no/tool.  Most cases
of defined used `yes' anyway; fix the few stragglers do that instead.
New case `tool' is for TOOL_DEPENDS rather than buildlink3.

Log message:
Allow building Xen infrastructure with Clang. Fix various bugs in
xenkernel3, xenkernel41, xentools3 and xentools41 exposed by Clang
default warnings. Bump revisions for those.

Log message:
'EXTRACT_SUFX is ".tar.gz" by default, so this definition may be
redundant.' - It was. Removed.

Log message:
Drop superfluous PKG_DESTDIR_SUPPORT, "user-destdir" is default these days.

Log message:
copy security patch from xenkernel41 - it also applies to 3.3
(noticed by Daniel Horecki)
bump PKGREV

Log message:
Apply fixes for gcc 4.5.
Fixes PR 45388. Bump pkg revision.

Log message:
Add a MESSAGE so we can pinpoint to the right location for Xen. Add
license.