Add the ability to chmod files in the overlay.

[djnym]

Two types are supported, direct chmoding, like

{chmod, 8#00700, "path/to/file/maybe/with/{{templates}}" }

or templating the permission where you have a template var like

{file_perm, 8#00700}

and an overlay

{chmod, "{{file_perm}}","path/to/file/maybe/with/{{templates}}" }

[lrascao]

👍 thanks!