add descriptive subsystem name string

src/backend/enginefacade.cpp

@@ -32,6 +32,7 @@ namespace backend {
   class EngineSubsysDescriptor
     : public Subsys
     {
+      operator string () { return "Engine"; }
       
       bool 
       shouldStart (lumiera::Option&)

src/backend/netnodefacade.cpp

@@ -32,6 +32,7 @@ namespace backend {
   class NetNodeSubsysDescriptor
     : public Subsys
     {
+      operator string () { return "Renderfarm node"; }
       
       bool 
       shouldStart (lumiera::Option&)

src/backend/scriptrunnerfacade.cpp

@@ -32,6 +32,7 @@ namespace backend {
   class ScriptRunnerSubsysDescriptor
     : public Subsys
     {
+      operator string () { return "Script runner"; }
       
       bool 
       shouldStart (lumiera::Option&)

src/lumiera/guifacade.cpp

@@ -32,6 +32,7 @@ namespace gui {
   class GuiSubsysDescriptor
     : public Subsys
     {
+      operator string () { return "Lumiera GTK GUI"; }
       
       bool 
       shouldStart (lumiera::Option&)

src/lumiera/subsys.hpp

@@ -77,6 +77,9 @@ namespace lumiera {
       
       virtual ~Subsys();
       
+      /** a human readable name */
+      virtual operator string ()  =0;
+
       
       /** define a dependency to another Subsys
        *  required for running this subsystem */

src/proc/facade.cpp

@@ -33,6 +33,7 @@ namespace proc {
   class BuilderSubsysDescriptor
     : public Subsys
     {
+      operator string () { return "Builder"; }
       
       bool 
       shouldStart (lumiera::Option&)
@@ -61,6 +62,7 @@ namespace proc {
   class SessionSubsysDescriptor
     : public Subsys
     {
+      operator string () { return "Session"; }
       
       bool 
       shouldStart (lumiera::Option&)