Move IEditor::isTemporary to IDocument

It's a property of the document implementation, not of the specific
editor instance working on it.

Change-Id: I5c3dd054e21b646e2d94b891916a096d045923f8
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/debugger/debuggerinternalconstants.h

@@ -46,7 +46,6 @@ namespace Internal {
 
 const char OPENED_BY_DEBUGGER[]         = "OpenedByDebugger";
 const char OPENED_WITH_DISASSEMBLY[]    = "DisassemblerView";
-const char OPENED_WITH_MEMORY[]         = "MemoryView";
 
 // Debug action
 const char DEBUG[]                      = "Debugger.Debug";