Debugger: Remove unused 'precise breakpoints' setting.

Remove break window menu action to toggle 'Full path'.
Remove gdb setting 'Use full path'.
Clean up break dialog:
- Set PathChooser::ExpectedKind before value (showed up in red).
- Use PathChooser::setPath()/path() instead of lineedit text
- Return thread spec
- Add validator for ignorecount as for breakcondition.ui
Remove unused fields from breakcondition.ui

Reviewed-by: hjk
Task-number: QTCREATORBUG-2593

src/plugins/debugger/breakhandler.cpp

@@ -283,10 +283,10 @@ QVariant BreakHandler::data(const QModelIndex &mi, int role) const
     if (mi.row() >= size())
         return QVariant();
 
-    const BreakpointData *data = at(mi.row());
+    BreakpointData *data = at(mi.row());
 
     if (role == BreakpointRole)
-        return qulonglong(data);
+        return qVariantFromValue(data);
 
     if (role == BreakpointUseFullPathRole)
         return data->useFullPath;