Issue #439: Widen Formula Dialog (dismine/valentina)

New issue 439: Widen Formula Dialog https://bitbucket.org/valentinateam/valentina/issues/439/widen-formula-dialog

Susan Spencer:

The Formula Dialog is too narrow to read the items in the selection box.
The user cannot widen it to read values.
The scrollbar is good but it would be better to be able to read the full string.

WidenFormulaDialog.png