A list of files and directories to install in the volume from cfg and sec keys.

	<path> from <path|relpath> key <key> [mode <mode>] [user <user>] [group <group>] [signal <sig>:<rid>]
	<path>/ [mode <mode>] [user <user>] [group <group>] [signal <sig>:<rid>]

Where the namespace default value is the namespace of the declaring object.
Where the perm, user and group default values are defined by the mode, user
and group volume keyword.

If no `from` definition is found, a directory is created as <path>.

When a `from` definition is found, files are created in <path>, with
their content fetched from sec or cfg objects.

Example:

	[volume#1]
	type = shm
	size = 1m
	install =
	  /etc/ mode 0750 user 1000 group 1000
	  /etc/ssl/ mode 0700 user 1000 group 1000
	  /etc/ from test/cfg/haproxy key haproxy.cfg mode 0640 user 1000 group 1000 signal HUP:container#haproxy
	  /etc/ssl/front.pem from ./sec/d key fullpem mode 0640 user 1000 group 1001 required
	  /etc/ssl/front.chain from ./sec/d key certificate_chain required
	  /etc/profile.d/ from ./sec/d key etc/profile.d/*
	  /data/

