Drafts and scheduled posts (#217)

closes #100
closes #59

* enable saving as draft (scheduled)
* add scheduled posts list
* fix NoSuchMethodError
* editable drafts/scheduled posts
* ui for drafts
* use instants between 9999-01-01 and 9999-12-31
* use save and draft strings
* map scheduled status params to status
* implement scheduling posts
* improve save/discard draft dialog
* persist scheduled date in state
* add unsent posts button to toolbar
* clean up imports

mastodon/src/main/java/org/joinmastodon/android/model/Poll.java

@@ -57,6 +57,11 @@ public class Poll extends BaseModel{
 		public String title;
 		public Integer votesCount;
 
+		public Option() {}
+		public Option(String title) {
+			this.title = title;
+		}
+
 		@Override
 		public String toString(){
 			return "Option{"+

mastodon/src/main/java/org/joinmastodon/android/model/ScheduledStatus.java

@@ -0,0 +1,79 @@
+package org.joinmastodon.android.model;
+
+import org.joinmastodon.android.api.RequiredField;
+import org.joinmastodon.android.model.Poll.Option;
+import org.parceler.Parcel;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Parcel
+public class ScheduledStatus extends BaseModel implements DisplayItemsParent{
+    @RequiredField
+    public String id;
+    @RequiredField
+    public Instant scheduledAt;
+    @RequiredField
+    public Params params;
+    @RequiredField
+    public List<Attachment> mediaAttachments;
+
+    @Override
+    public String getID() {
+        return id;
+    }
+
+    @Parcel
+    public static class Params {
+        @RequiredField
+        public String text;
+        public String spoilerText;
+        @RequiredField
+        public StatusPrivacy visibility;
+        public long inReplyToId;
+        public ScheduledPoll poll;
+        public boolean sensitive;
+        public boolean withRateLimit;
+        public String language;
+        public String idempotency;
+        public String applicationId;
+        public List<String> mediaIds;
+    }
+
+    @Parcel
+    public static class ScheduledPoll {
+        @RequiredField
+        public String expiresIn;
+        @RequiredField
+        public List<String> options;
+        public boolean multiple;
+        public boolean hideTotals;
+
+        public Poll toPoll() {
+            Poll p = new Poll();
+            p.voted = true;
+            p.emojis = List.of();
+            p.ownVotes = List.of();
+            p.multiple = multiple;
+            p.options = options.stream().map(Option::new).collect(Collectors.toList());
+            return p;
+        }
+    }
+
+    public Status toStatus() {
+        Status s = new Status();
+        s.id = id;
+        s.mediaAttachments = mediaAttachments;
+        s.createdAt = scheduledAt;
+        s.content = s.text = params.text;
+        s.spoilerText = params.spoilerText;
+        s.visibility = params.visibility;
+        s.language = params.language;
+        s.mentions = List.of();
+        s.tags = List.of();
+        s.emojis = List.of();
+        if (params.poll != null) s.poll = params.poll.toPoll();
+        return s;
+    }
+}