Implement a font setting

[ghost]

see http://goldendict.org/forum/viewtopic.php?f=4&t=1035

A font setting in the preferences window would come in handy.

[CFynn]

For multilingual dictionaries a font setting should allow specification by Unicode Range, Script or Language

[tovaremeterio]

A font setting preferences for GD would be extremely useful. Especially while using chinese characters.

[Eosphorus]

A font button on the toolbar or at least an entry in the menu would be so much more convenient than having to fiddle with the various stylesheets.