LDAP support

[neoice]

I've had the following in my [global] config for years:

	security = user
	encrypt passwords = true
	passdb backend = ldapsam:ldap://127.0.0.1
	ldap admin dn = "cn=smbadin,dc=neoice,dc=net"
	ldap suffix = dc=neoice,dc=net
	ldap ssl = off
	ldap passwd sync = yes

I was sad to see that none of the LDAP options are supported.

[ajjahn]

These option could be added to https://github.com/ajjahn/puppet-samba/blob/master/manifests/server.pp pretty easily. If you're willing to submit a PR with tests, I'd merge it in.