Fix some Disc build errors

Detail:
  Makefiles/AAsmModule - Reintroduce IfThere check of LocalRes:Messages, so that components which don't have any messages file will build correctly once again
  Makefiles/CApp - Ensure ${INSERTVERSION}'d files are writable; fixes errors when performing repeated Disc builds of components which mark their install directory tree as readonly.
Admin:
  Fixes issue reported on forums with DDEUtils not being present in recent disc images:
  https://www.riscosopen.org/forum/forums/11/topics/2848


Version 6.51. Tagged as 'BuildSys-6_51'

Makefiles/AAsmModule

@@ -177,7 +177,7 @@ ${MERGEDMSGS}${PRIVATEMSGS}:
         ${MKDIR} ${MERGEDMDIR}
         ${TOKENCHECK} LocalRes:Messages
         IfThere LocalRes:CmdHelp Then ${TOKENCHECK} LocalRes:CmdHelp
-        IfThere LocalRes:CmdHelp Then ${FAPPEND} $@ LocalRes:Messages LocalRes:CmdHelp Else ${CP} LocalRes:Messages $@ ${CPFLAGS}
+        IfThere LocalRes:CmdHelp Then ${FAPPEND} $@ LocalRes:Messages LocalRes:CmdHelp Else IfThere LocalRes:Messages Then ${CP} LocalRes:Messages $@ ${CPFLAGS}
 
 install${CUSTOMSA}: ${SA_MODULE}
         ${MKDIR} ${INSTDIR}

Makefiles/CApp

@@ -63,6 +63,7 @@ INCLUDED_CAPP = YES
 # ECHO
 # TOUCH            (create/touch)
 # INSERTVERSION    (awk script to substitute from VersionNum)
+# CHMOD            (file permission manipulation)
 #
 #
 # It relies on the following from the StdRules makefile
@@ -145,12 +146,15 @@ install_app${CUSTOMINSTALLAPP}: ${INSTAPP_DEPENDS}
         ${MKDIR} ${INSTAPP}
         ${INSTRES} -I Resources.${USERIF}.${LOCALE},Resources.${USERIF}.UK,Resources.${LOCALE},Resources.UK,Resources ${INSTAPP} ${INSTAPP_FILES}
 ifneq (,$(filter Messages,${INSTAPP_VERSION}))
+        ${CHMOD} +w ${INSTAPP}.Messages
         ${INSERTVERSION} LocalRes:Messages > ${INSTAPP}.Messages
 endif        
 ifneq (,$(filter Desc,${INSTAPP_VERSION}))
+        ${CHMOD} +w ${INSTAPP}.Desc
         ${INSERTVERSION} descmode=1 LocalRes:Desc > ${INSTAPP}.Desc
 endif        
 ifneq (,$(filter !Run,${INSTAPP_VERSION}))
+        ${CHMOD} +w ${INSTAPP}.!Run
         ${INSERTVERSION} obeymode=1 LocalRes:!Run > ${INSTAPP}.!Run
         ${SETTYPE} ${INSTAPP}.!Run Obey
 endif        

VersionNum

-/* (6.50)
+/* (6.51)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        6.50
+#define Module_MajorVersion_CMHG        6.51
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                24 Sep 2014
+#define Module_Date_CMHG                01 Oct 2014
 
-#define Module_MajorVersion             "6.50"
-#define Module_Version                  650
+#define Module_MajorVersion             "6.51"
+#define Module_Version                  651
 #define Module_MinorVersion             ""
-#define Module_Date                     "24 Sep 2014"
+#define Module_Date                     "01 Oct 2014"
 
-#define Module_ApplicationDate          "24-Sep-14"
+#define Module_ApplicationDate          "01-Oct-14"
 
 #define Module_ComponentName            "BuildSys"
 #define Module_ComponentPath            "castle/RiscOS/BuildSys"
 
-#define Module_FullVersion              "6.50"
-#define Module_HelpVersion              "6.50 (24 Sep 2014)"
-#define Module_LibraryVersionInfo       "6:50"
+#define Module_FullVersion              "6.51"
+#define Module_HelpVersion              "6.51 (01 Oct 2014)"
+#define Module_LibraryVersionInfo       "6:51"