Fixed normal EXT-6812 ([TRUNCATION] APARIENCIA window > Forma > Boca > Labios: prominec. \"Labios: prominenc\" should be \"Labios: prominencia\".)

- There was two reasons:
1. Uninitialized variable in llsliderctrl.(h/cpp) that contains label size. This variable take part in calculation of TextBox size of label.
2. Font of 'label string' and text box was different. This causes wrong calculation of 'label string' length.

Reviwed by Vadim Savchuk and Mike Antipov at https://codereview.productengine.com/secondlife/r/246/

--HG--
branch : product-engine