Add support for scoped queries

This work adds support for setting the scope of a given query.  This
allows retrieval of a specific objects, or searching at a specific level
of the tree for the desired results.

lib/puppet/parser/functions/ldapquery.rb

@@ -1,3 +1,11 @@
+# Provides a query interface to an LDAP server
+#
+# @example simple query
+#   ldapquery("(objectClass=dnsDomain)", ['dc'])
+#
+# @example more complex query for ssh public keys
+#   ldapquery('(&(objectClass=ldapPublicKey)(sshPublicKey=*)(objectClass=posixAccount))', ['uid', 'sshPublicKey'])
+#
 require_relative '../../../puppet_x/ldapquery'
 
 begin
@@ -9,14 +17,15 @@ end
 Puppet::Parser::Functions.newfunction(:ldapquery,
                                       :type => :rvalue) do |args|
 
-  if args.size > 3
+  if args.size > 4
     raise Puppet::ParseError, "Too many arguments received in ldapquery()"
   end
 
-  filter, attributes, base = args
+  filter, attributes, base, scope = args
 
   attributes ||= []
   base ||= Puppet[:ldapbase]
+  scope ||= 'sub'
 
-  return PuppetX::LDAPquery.new(filter, attributes, base).results
+  return PuppetX::LDAPquery.new(filter, attributes, base, scope).results
 end