Update URLs and names in README.md
Update URLs and names in README.md

* Follow redirects on URLs (mostly changing http to https)
* Capitalize Homebrew and change Mac OS X to macOS
* Use the MacPorts homepage, instead of the old Subversion repository
gnowxilef/pianobar,gnowxilef/pianobar,gnowxilef/pianobar,gnowxilef/pianobar,gnowxilef/pianobar,gnowxilef/pianobar