Add "falafel" custom date/time field type and widget

finally able to edit datetime fields, but feels like a lot of
assumptions to make, just to determine time zone..so keeping naive UTC
on the backend still, and naive local on the frontend

in general this needs more polish, but is a start..

tailbone/static/js/tailbone.buefy.timepicker.js

@@ -9,15 +9,55 @@ const TailboneTimepicker = {
         'placeholder="Click to select ..."',
         'icon-pack="fas"',
         'icon="clock"',
+        ':value="value ? parseTime(value) : null"',
         'hour-format="12"',
+        '@input="timeChanged"',
+        ':time-formatter="formatTime"',
         '>',
         '</b-timepicker>'
     ].join(' '),
 
     props: {
         name: String,
-        id: String
-    }
+        id: String,
+        value: String,
+    },
+
+    methods: {
+
+        formatTime(time) {
+            if (time === null) {
+                return null
+            }
+
+            let h = time.getHours()
+            let m = time.getMinutes()
+            let s = time.getSeconds()
+
+            h = h < 10 ? '0' + h : h
+            m = m < 10 ? '0' + m : m
+            s = s < 10 ? '0' + s : s
+
+            return h + ':' + m + ':' + s
+        },
+
+        parseTime(time) {
+
+            if (time.getHours) {
+                return time
+            }
+
+            let found = time.match(/^(\d\d):(\d\d):\d\d$/)
+            if (found) {
+                return new Date(null, null, null,
+                                parseInt(found[1]), parseInt(found[2]))
+            }
+        },
+
+        timeChanged(time) {
+            this.$emit('input', time)
+        },
+    },
 }
 
 Vue.component('tailbone-timepicker', TailboneTimepicker)