Revert "Enabled the use of Debugger-specific watch/locals models."

This reverts commit abf5e3ddc3.

src/plugins/debugger/debugger.pro

@@ -44,8 +44,6 @@ HEADERS += \
     sourcefileswindow.h \
     threadswindow.h \
     watchhandler.h \
-    asyncwatchmodel.h \
-    abstractsyncwatchmodel.h \
     watchwindow.h \
 
 SOURCES += \
@@ -73,8 +71,6 @@ SOURCES += \
     sourcefileswindow.cpp \
     threadswindow.cpp \
     watchhandler.cpp \
-    asyncwatchmodel.cpp \
-    abstractsyncwatchmodel.cpp \
     watchwindow.cpp \
 
 FORMS += attachexternaldialog.ui \