base

If the cursor moves from a focused textfield to another, remove the WebTextView.

We already remove the blinking caret, implying that if the user
types with the cursor on another textfield, the keys will go there.
This way, the WebView will see the key, and rebuild the WebTextView,
so we no longer use the data from the first textfield.  This fixes
a bug where moving from a focused textfield and pressing delete
with the cursor on another was deleting a character from the
first (initially focused) textfield.  Also, in WebView::onKeyDown,
only check if the native cursor is a textfield before deciding
whether to send a CLICK, since plugins will be handled differently
(this is part of a different change), and now the cursor may match
the focus, but we still want the click (to make the focusController
active - i.e. make the cursor blink).