Fix #1469 - Add an option to recurse only on remote side

When using recurse and a source, if the client side has many files
it can take a lot of CPU/memory to checksum the whole client
hierarchy. The idea is that it is not necessary to recurse on the
client side if all we want is to manage the files that are sourced
from the server.

This changeset adds the "remote" recurse value which prevents recursing
on the client side when a source is present. Since it also is necessary
to limit the remote side recursion a new File{} parameter has been
added called "recurselimit".

Moreover, the Filetset API is changing to allow the new recurselimit
parameter, and passing the recursion depth limit in the recurse parameter
as an integer is now deprecated and not supported anymore.

Signed-off-by: Brice Figureau <brice-puppet@daysofwonder.com>