Improvement of formatting in text preview of palette wizards

In JQM 1.4 some widgets are set with classes, for example

<a href="#" class="ui-btn ui-mini ui-corner-all ui-icon-plus ui-btn-icon-left">

which makes class attribute too long to fit into line.
Let's allow starting new line at space inside quotas for text preview. That will not affect generation of text to insert.