Steven Köhler

I found that the placeholder text of a `WLineEdit` widget, that was set by `WLineEdit::setPlaceholderText(WString::tr("..."))` does not update when changing the `WApplication`'s locale, as described in [Issue 11156](https://redmine.emweb.be/issues/11156). This pull...

This pull request contains the changes needed for [WT-13676](https://redmine.emweb.be/issues/13676) to support self-deleting `Wt::Http::Client`.