This reverts commit ebe2bd4e.

Regression after commit 6c09c26d.

An uninitialized variable had been used in the code, which could
lead to a crash when the code was executed.

Bug 761883 - Freeze when editing a specific Draft: GLib-GObject-WARNING **: invalid cast from 'WebKitDOMText' to 'WebKitDOMElement'

Bug title says everything. Don't try to cast a text to element.

This does not apply just on the Unicode emoticons, but for the image ones as well.
While working on this I reworked hot the Unicode smileys are inserted to the
composer. Before they were inserted inside a SPAN element and this caused some
problems, after this change they are inserted as text.

First check if there is something after the selection end, if nothing move to the
selection start, not in reversed order.

Use the right variable when getting the text node with smiley.

As discussed in bug #760951, drag & drop from the minicard view
into the source selector results in a state where there cannot be
clicked anything, but the minicard view again. That was due to left
grab on the minicard view canvas, while it should be released,
the same as it is released on button release in other cases.