ui.resizable >> !respecting min height || width

min height || width is not respected when the data.height === 0 as calculated from this._change passed from this.mouseDrag

result: box jump the size of min height || width since data.height=0 gets passed through

fix:

(1) add new function to 'this' to detect nothing but allow zero

this._isNothing: function(x) {return x === undefined || x === null},

(2) _respectSize:

isminw = !this._isNothing(data.width) && (o.minWidth && data.width < o.minWidth),

isminh = !this._isNothing(data.height) && (o.minHeight && data.height < o.minHeight);