Merge branch 'fc/zsh-completion'

Zsh autocompletion (in contrib/) update. * fc/zsh-completion: (29 commits) zsh: update copyright notices completion: bash: remove old compat wrappers completion: bash: cleanup cygwin check completion: bash: trivial cleanup completion: zsh: add simple version check completion: zsh: trivial simplification completion: zsh: add alias descriptions completion: zsh: improve command tags completion: zsh: refactor command completion completion: zsh: shuffle functions around completion: zsh: simplify file_direct completion: zsh: simplify nl_append completion: zsh: trivial cleanup completion: zsh: simplify direct compadd completion: zsh: simplify compadd functions completion: zsh: fix splitting of words completion: zsh: add missing direct_append completion: fix conflict with bashcomp completion: zsh: fix completion for --no-.. options completion: bash: remove zsh wrapper ...