Remove some more expired ports:

devel/py-backports.functools_lru_cache
devel/py-backports_abc
devel/py-futures
devel/py-singledispatch
devel/py-typing
graphics/py-pillow6

Adjust dependent ports.
Tested with 'make index' against r559975

Revert r559792 to unbreak INDEX and bulk -a
It seems a lot of reverse dependencies were missed

With hat:	portmgr

Remove most expired ports that depend on Python 2.7:

Exceptions are:
- mail/mailman, our listservers still use it
- www/chromium, solely because of popular demand,
  upstream is (slowly) working on porting it to Python 3
- ports that have actual patches for Python 3 against
  them (Cinnamon and a few unrelated other ports)
- llvm70 and qt5-webengine because they seem to have a lot
  of dependencies which need further analysis
- sysutils/uefi-edk2-bhyve because bhyve seems to use them
- python2 and python27 themselves

I'm sure there will be complaints, but the nice thing about
a version control system is that we can revert and adjust things.

Use PY_FLAVOR for dependencies.

FLAVOR is the current port's flavor, it should not be used outside of
this scope.

Sponsored by:	Absolight

Switch all pypi.python.org WWWs to a new PyPi home pypi.org where
they now redirect to anyway. All new urls checked to return 200,
I've fixed a couple of them in the process.

Approved by:	portmgr blanket, mat

Update to 1.5

Changes:	https://github.com/jaraco/backports.functools_lru_cache/blob/master/CHANGES.rst

Clean up Makefile

add devel/py-backports - namespace shim for Python backports

Currently, all py-backports.* ports conflict with each other
over a file that has the same contents.

This creates a port that installs the shared file and py-backports.*
ports should depend on this one and remove the shared file from their
own pkg-plist. It's the same approach as the one taken by OpenBSD.

Some ports are already converted as an example:
- security/py-backports.ssl_match_hostname
- devel/py-backports.functools_lru_cache
- devel/py-backports.shutil_get_terminal_size

The last two conversions and the fix to work with FLAVORS were submitted
by antoine. Thank you!

Reviewed by:	antoine
Approved by:	portmgr (antoine)
Differential Revision:	https://reviews.freebsd.org/D11095

Convert Python ports to FLAVORS.

  Ports using USE_PYTHON=distutils are now flavored.  They will
  automatically get flavors (py27, py34, py35, py36) depending on what
  versions they support.

  There is also a USE_PYTHON=flavors for ports that do not use distutils
  but need FLAVORS to be set.  A USE_PYTHON=noflavors can be set if
  using distutils but flavors are not wanted.

  A new USE_PYTHON=optsuffix that will add PYTHON_PKGNAMESUFFIX has been
  added to cope with Python ports that did not have the Python
  PKGNAMEPREFIX but are flavored.

  USES=python now also exports a PY_FLAVOR variable that contains the

Update to 1.4

Changes:	https://github.com/jaraco/backports.functools_lru_cache/blob/master/CHANGES.rst

Take maintainership

- Add NO_ARCH
- Update COMMENT
- Update pkg-descr
- Add PyPI as primary WWW

Reset mva@'s ports, he handed in his ports bit.

A backport of the lru_cache function from Python 3.3's functools.

WWW: https://github.com/jaraco/backports.functools_lru_cache