Use more https in urls and updated some lost links

Library/Homebrew/blacklist.rb

Library/Homebrew/cmd/aspell-dictionaries.rb

Library/Homebrew/cmd/create.rb

Library/Homebrew/cmd/doctor.rb

Library/Homebrew/cmd/search.rb

Library/Homebrew/download_strategy.rb

Library/Homebrew/extend/ENV/shared.rb

Library/Homebrew/os/mac.rb

Library/Homebrew/os/mac/xcode.rb

Library/Homebrew/os/mac/xquartz.rb

Library/Homebrew/requirements.rb

Library/Homebrew/requirements/mpi_dependency.rb

Library/Homebrew/version.rb