Skip some unused libraries

Don't build or export non participants MemLib & SCInterface.

Components/ROOL/Disc

@@ -37,6 +37,7 @@ DOSFS                   -type EXP       # FileSys.ImageFS.DOSFS
 DragAnObj               -type EXP       # Desktop.DragAnObj
 DragASprite             -type EXP       # Desktop.DragASprit
 DrawMod                 -type EXP       # Video.Render.Draw
+Econet                  -type EXP       # Networking.Econet
 Filer_Action            -type EXP       # Desktop.FilerAct
 FileSwitch              -type EXP       # FileSys.FileSwitch
 FilterManager           -type EXP       # Desktop.Filter
@@ -109,19 +110,14 @@ OSLib                   -type EXP       # Lib.OSLib
 UnicodeLib              -type EXP       # Lib.Unicode
 DeskLib                 -type EXP       # Lib.Desk
 ModMallocLib            -type EXP       # Lib.ModMalloc
-###MemCheckLib             -type EXP       # Lib.MemCheck
-#ModuleTaskLib           -type EXP       # Lib.ModuleTask
 PlainArgvLib            -type EXP       # Lib.PlainArgv
 RemoteDebug             -type EXP       # Lib.remotedb
-#AcornNCLib              -type EXP       # Lib.AcornNC
 PDebug                  -type EXP       # Lib.PDebug
 DDTLib                  -type EXP       # Lib.DDTLib
 Wild                    -type EXP       # Lib.Wild
 Trace                   -type EXP       # Lib.Trace
 DebugLib                -type EXP       # Lib.DebugLib
-###C++Lib                  -type EXP       # Lib.C++Lib
 AsmUtils                -type EXP       # Lib.AsmUtils
-#HTMLLib                 -type EXP       # Lib.HTML
 callx                   -type EXP       # Lib.callx
 zlib                    -type EXP       # Lib.zlib
 PRISMLib                -type EXP       # Lib.PRISMLib
@@ -129,14 +125,9 @@ PRISMLib                -type EXP       # Lib.PRISMLib
 #
 # Other header and library exports for the Universal build...
 #
-###ARLib                    -type EXP      # Lib.ARLib
 ConfigLib                -type EXP      # Lib.Configure
-###Dialler                  -type EXP      # Networking.Modem.Dialler
-Econet                   -type EXP      # Networking.Econet
 KeyWatch                 -type EXP      # Programmer.KeyWatch
-MemLib                   -type EXP      # Lib.MemLib
 RMVersion                -type EXP      # Programmer.RMVersion
-SCInterface              -type EXP      # HWSupport.SmartCard.SCInter
 SoundControl             -type EXP      # Audio.SoundCtrl
 SpriteExtend             -type EXP      # Video.Render.SprExtend         <- also included as installed component
 USBDriver                -type EXP      # HWSupport.USB.NetBSD