Debuggers: Enable Python-dumpers for Windows-built gdb.

Engine: Introduce convention of setting the PYTHONPATH
variable to <path-to-gdb>\python2.5 for WIndows.

Dumpers: Import 'curses' depending on platform, fix Syntax
for 2.5, catch file lock errors by os.remove.
Reviewed-by: hjk

src/plugins/debugger/debuggeractions.cpp

@@ -284,7 +284,11 @@ DebuggerSettings *DebuggerSettings::instance()
     //
     item = new SavedAction(instance);
     item->setSettingsKey(debugModeGroup, QLatin1String("Location"));
-    item->setDefaultValue("gdb");
+#ifdef Q_OS_WIN
+    item->setDefaultValue(QLatin1String("gdb-i686-pc-mingw32.exe"));
+#else
+    item->setDefaultValue(QLatin1String("gdb"));
+#endif
     instance->insertItem(GdbLocation, item);
 
     item = new SavedAction(instance);