Log message:
Bump for perl-5.20.0.
Do it for all packages that
* mention perl, or
* have a directory name starting with p5-*, or
* depend on a package starting with p5-
like last time, for 5.18, where this didn't lead to complaints.
Let me know if you have any this time.

Log message:
Mark packages that are not ready for python-3.3 also not ready for 3.4,
until proven otherwise.

Log message:
Remove example rc.d scripts from PLISTs.

These are now handled dynamically if INIT_SYSTEM is set to "rc.d", or
ignored otherwise.

Log message:
No need to have two variables for the same logic.
Replace PYTHON_PATCH_SCRIPTS with REPLACE_PYTHON.

Log message:
Mark packages as not ready for python-3.x where applicable;
either because they themselves are not ready or because a
dependency isn't. This is annotated by
PYTHON_VERSIONS_INCOMPATIBLE=  33 # not yet ported as of x.y.z
or
PYTHON_VERSIONS_INCOMPATIBLE=  33 # py-foo, py-bar
respectively, please use the same style for other packages,
and check during updates.

Use versioned_dependencies.mk where applicable.
Use REPLACE_PYTHON instead of handcoded alternatives, where applicable.
Reorder Makefile sections into standard order, where applicable.

Remove PYTHON_VERSIONS_INCLUDE_3X lines since that will be default
with the next commit.

Whitespace cleanups and other nits corrected, where necessary.

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

Log message:
Fix header guards.

Log message:
Replace py-curses/buildlink3.mk with DEPENDS.

There are no buildlink3-relevant files here, just a loadable module.

Log message:
Bump all packages for perl-5.18, that
a) refer 'perl' in their Makefile, or
b) have a directory name of p5-*, or
c) have any dependency on any p5-* package

Like last time, where this caused no complaints.

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.