Add Qt 4.8.7 for GUI support to Linux and macOS builds

update import behaviour

fix readme note

minor changes to readmes

update README to reflect recent changes

Revert "bump OpenCV version to 3.2.0"

This reverts commit 3396bdf.

add rule for py36 for macOS [skip appveyor]

New release (Windows wheels include now FFmpeg).

New release (OS X py35 support added).

fix some minor bugs