VUX V2.7.9 released

Clocker

• [fix] fix bug when initial value is empty string #2449

Panel

• [fix] hide footer when footer.title is empty #2476

Picker

• [fix] fix typo item_class => itemClass #2457

Rater

• [feature] prop:min add min value #2439

XInput

• [enhance] support china union 166 prefix phone number

Bus

• [fix] add bus to this.$vux