Issue #424: Improve Formula Wizard dialog. (dismine/valentina)

New issue 424: Improve Formula Wizard dialog. https://bitbucket.org/valentinateam/valentina/issues/424/improve-formula-wizard-dialog

Roman Telezhinskyi:

The Formula Wizard already contains a lot of data. But users don’t have information about functions they could use in a formula. I propose to add additional section for this.