Datepicker: Don't set _curInst in hideDatepicker. Fixes #8174 - jQuery datepicker is stuck open if label is clicked from open state.

(cherry picked from commit 4ade134)

Conflicts:

	ui/jquery.ui.datepicker.js

Author: scottgonzalez

ui/jquery.ui.datepicker.js

@@ -800,10 +800,8 @@ $.extend(Datepicker.prototype, {
 		if (this._datepickerShowing) {
 			var showAnim = this._get(inst, 'showAnim');
 			var duration = this._get(inst, 'duration');
-			var self = this;
 			var postProcess = function() {
 				$.datepicker._tidyDialog(inst);
-				self._curInst = null;
 			};
 			if ($.effects && $.effects[showAnim])
 				inst.dpDiv.hide(showAnim, $.datepicker._get(inst, 'showOptions'), duration, postProcess);