Add ~/Applications to search path for VLC

This adds the ~/Applications` to the search path for the VLC.app on Darwin (Mac OS X).
It's for those that have installed VLC to their account only.
Merge pull request #454 from maxnordlund/patch-1

Add ~/Applications to search path for VLC
Update AUTHORS.
Update CHANGELOG.rst.
docs: Update theme.
docs: Add a extension that allows links to reference current release.
docs: Clean up the install page.
docs: Minor tweaks.
Release version 1.9.0.
Merge branch 'release/1.9.0' into develop
cli: Whoops, forgot to actually apply some of the HDS options.
cli.argparser: Improve the number validation.
stream.segmented: Add support for multi-threaded segment downloading.

Resolves #338.
Update CHANGELOG.rst.
docs: Update dependencies.
win32: Update dependencies.
cli: Close currently running stream on keyboard interrupt.