Fixed normal bug EXT-6581 ('Buy' floater looks corrupted after size reducing)

-increased floater minimal width
-decreased width of TextBox with truncated string and used 'use_ellipses' for it
-deleted overriden button width dimension in DE locale

Reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/315/

--HG--
branch : product-engine