gapi: langpuppet: Add initial implementation

This new entrypoint allows graph generation from both a Puppet manifest
and a piece of mcl code. The GAPI implementation wraps the two existing
GAPIs.

lib/deploy.go

@@ -27,6 +27,7 @@ import (
 	"github.com/purpleidea/mgmt/gapi"
 	// these imports are so that GAPIs register themselves in init()
 	_ "github.com/purpleidea/mgmt/lang"
+	_ "github.com/purpleidea/mgmt/langpuppet"
 	_ "github.com/purpleidea/mgmt/puppet"
 	_ "github.com/purpleidea/mgmt/yamlgraph"