Add dev-python/pyqtgraph

Package-Manager: portage-2.2.1
add [${PYTHON_USEDEP}] to depencies to sastify python-r1

Package-Manager: portage-2.2.1
remove untested keywords

Package-Manager: portage-2.2.1
Merge pull request #106 from gpoulin/master

Add dev-python/pyqtgraph