Keep to the proper namespace for helper classes in vm::guest.

When defining more than one class/define in the same file, Puppet 5
requires them to be named so that they are "under" the main class.
Rename helper classes to be vm::guest:: instead of just vm::.

manifests/guest.pp

@@ -169,7 +169,7 @@ define vm::guest($ensure='installed', $autoboot=true, $virtmethod='xenpv',
 		    $mounts=[], $netconfig='--static-auto', $rootpw='',
 		    $os='centos-7', $arch=$architecture)
 {
-    include vm::anacondafiles
+    include vm::guest::anacondafiles
     include vm::osparams
 
     # Find out OS specific parameters
@@ -212,7 +212,7 @@ define vm::guest($ensure='installed', $autoboot=true, $virtmethod='xenpv',
 
             $nodash_os = regsubst($os, '-', '_', 'G')
 
-	    include vm::network_bridging
+	    include vm::guest::network_bridging
 	    include "vm::osinst::${nodash_os}::${arch}"
 	    include vm::guests::blacklist_hw_drivers
             include puppet
@@ -298,7 +298,7 @@ define vm::guest($ensure='installed', $autoboot=true, $virtmethod='xenpv',
 
 # Help classes.
 
-class vm::anacondafiles
+class vm::guest::anacondafiles
 {
     include xen::dom0
     include env::package::mkisofs
@@ -321,7 +321,7 @@ class vm::anacondafiles
 }
 
 
-class vm::network_bridging
+class vm::guest::network_bridging
 {
     # Newer kernels (not in 3.18 in Xen4CentOS6, but 4.9 does) pass bridged
     # packets through iptables FORWARD chain by default.  We must disable