graphics/py-sane: new port

Python interface to the SANE scanner and frame grabber interface
https://github.com/python-pillow/Sane

Remove deprecated ports:

2020-08-15 archivers/py-backports.lzma: Uses deprecated version of python
2020-08-15 archivers/py-bup: Uses deprecated version of python
2020-08-15 archivers/py-librtfcomp: Uses deprecated version of python
2020-08-15 audio/blop-lv2: Uses deprecated version of python
2020-08-15 audio/bs2b-lv2: Uses deprecated version of python
2020-08-15 audio/py-gmusicproxy: Uses deprecated version of python
2020-08-15 audio/py-karaoke: Uses deprecated version of python
2020-08-15 audio/py-openal: Uses deprecated version of python
2020-08-15 audio/py-py-jack: Uses deprecated version of python
2020-08-15 audio/py-xmms2: Uses deprecated version of python
2020-08-15 audio/triceratops-lv2: Uses deprecated version of python
2020-08-15 biology/py-biom-format: Uses deprecated version of python
2020-08-15 comms/py-bulksms: Uses deprecated version of python

Convert the tree to use PY_PILLOW

With hat:	portmgr
Originally submitted by:	kai

graphics/py-pillow: Update to 7.0.0

* Repo-Copy the Pillow 6.2.2 release to graphics/py-pillow6 to retain
  backwards compatibility for Python 2 consumers as the Pillow 7.0.0 release
  dropped the support for Python 2.

* Apply conditional statements to use either Pillow 7.x or Pillow 6.x for
  consumers that can be built for Python 2 or newer.

* Exceptions are ports that can be built only for either Python 2 or
  Python 3.  For the first case, consumers are just assigned to the
  repo-copied graphics/py-pillow6.

* Also remove Pillow from BUILD_DEPENDS of math/py-PyWavelets as it is not
  listed in setup.py as a build dependency [1] and relax the version

Deprecate a few ports

With hat:	portmgr

Use PY_FLAVOR for dependencies.

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

Sponsored by:	Absolight

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

Remove ${PORTSDIR}/ from dependencies, categories d, e, f, and g.

With hat:	portmgr
Sponsored by:	Absolight

- Convert ports of graphics/ to new USES=python

Approved by:	portmgr (implicit)

Unbreak ocrfeeder, it depended on both py-imaging (via self+py-sane) and
py-pillow (via py-reportlab2)

- Stage
- Fix LIB_DEPENDS
- Pet portlint

PR:		ports/188954
Submitted by:	Bartek Rutkowski <ports@robakdesign.com>
Approved by:	Buganini <buganini@gmail.com> (maintainer)

Add NO_STAGE all over the place in preparation for the staging support (cat:
graphics)

Add py-sane 2.0, the Python binding for Sane.

PR:             ports/159544
Submitted by:   Kuan-Chung Chiu <buganini@gmail.com>
Approved by:    miwi, wen (mentors implicit)