Tab customization & direct messages tab (#1012)

* custom tabs

* custom tabs interface

* implement custom tab functionality

* add database migration

* fix bugs, improve ThemeUtils nullability handling

* implement conversationsfragment

* setup ConversationViewHolder

* implement favs

* add button functionality

* revert 10.json

* revert item_status_notification.xml

* implement more menu, replying, fix stuff, clean up

* fix tests

* fix bug with expanding statuses

* min and max number of tabs

* settings support, fix bugs

* database migration

* fix scrolling to top after refresh

* fix                                 bugs

* fix warning in item_conversation

app/src/main/java/com/keylesspalace/tusky/entity/Account.kt

@@ -37,13 +37,13 @@ data class Account(
         val avatar: String,
         val header: String,
         val locked: Boolean = false,
-        @SerializedName("followers_count") val followersCount: Int,
-        @SerializedName("following_count") val followingCount: Int,
-        @SerializedName("statuses_count") val statusesCount: Int,
-        val source: AccountSource?,
-        val bot: Boolean,
-        val emojis: List<Emoji>?,  // nullable for backward compatibility
-        val fields: List<Field>?,  //nullable for backward compatibility
+        @SerializedName("followers_count") val followersCount: Int = 0,
+        @SerializedName("following_count") val followingCount: Int = 0,
+        @SerializedName("statuses_count") val statusesCount: Int = 0,
+        val source: AccountSource? = null,
+        val bot: Boolean = false,
+        val emojis: List<Emoji>? = emptyList(),  // nullable for backward compatibility
+        val fields: List<Field>? = emptyList(),  //nullable for backward compatibility
         val moved: Account? = null
 
 ) : Parcelable {

app/src/main/java/com/keylesspalace/tusky/entity/Conversation.kt

@@ -0,0 +1,25 @@
+/* Copyright 2019 Conny Duck
+ *
+ * This file is a part of Tusky.
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tusky; if not,
+ * see <http://www.gnu.org/licenses>. */
+
+package com.keylesspalace.tusky.entity
+
+import com.google.gson.annotations.SerializedName
+
+data class Conversation(
+        val id: String,
+        val accounts: List<Account>,
+        @SerializedName("last_status") val lastStatus: Status,
+        val unread: Boolean
+)

app/src/main/java/com/keylesspalace/tusky/entity/Status.kt

@@ -42,7 +42,7 @@ data class Status(
         var pinned: Boolean?
 ) {
 
-    val actionableId: String?
+    val actionableId: String
         get() = reblog?.id ?: id
 
     val actionableStatus: Status