Add new keywords, and fix the *-alias highlighting

This adds a couple of new keywords, some are already in released Hy
versions, some are only on master. It also fixes the *-alias
highlighting: those take an array as the first argument.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Merge pull request #24 from algernon/f/more-keywords

Add new keywords, and fix the *-alias highlighting