Bump gocui

... and switch back from stefanhaller's tcell fork to the official tcell. This
basically reverts 7ccb871a45.

vendor/github.com/gdamore/tcell/v2/event.go

@@ -0,0 +1,53 @@
+// Copyright 2015 The TCell Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use file except in compliance with the License.
+// You may obtain a copy of the license at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tcell
+
+import (
+	"time"
+)
+
+// Event is a generic interface used for passing around Events.
+// Concrete types follow.
+type Event interface {
+	// When reports the time when the event was generated.
+	When() time.Time
+}
+
+// EventTime is a simple base event class, suitable for easy reuse.
+// It can be used to deliver actual timer events as well.
+type EventTime struct {
+	when time.Time
+}
+
+// When returns the time stamp when the event occurred.
+func (e *EventTime) When() time.Time {
+	return e.when
+}
+
+// SetEventTime sets the time of occurrence for the event.
+func (e *EventTime) SetEventTime(t time.Time) {
+	e.when = t
+}
+
+// SetEventNow sets the time of occurrence for the event to the current time.
+func (e *EventTime) SetEventNow() {
+	e.SetEventTime(time.Now())
+}
+
+// EventHandler is anything that handles events.  If the handler has
+// consumed the event, it should return true.  False otherwise.
+type EventHandler interface {
+	HandleEvent(Event) bool
+}