gsma: check args
theme: fix coloring of cwd
Use zsh's default for ':completion:*:hosts'

The manual configuration of ':completion:*:hosts' causes some problems
(e.g. issue #1337), and misses useful information (especially from
~/.ssh/known_hosts; issue #690 and issue #1009).

The best option appears to be using zsh's default configuration for
':completion:*:hosts'.

Conflicts:

	lib/completion.zsh