add support for tachiyomi extensions Lib 1.3 (#316)

* closes #315

* provide real values

* add support for tachiyomi extensions lib 1.3

server/src/main/kotlin/eu/kanade/tachiyomi/source/UnmeteredSource.kt

@@ -0,0 +1,8 @@
+package eu.kanade.tachiyomi.source
+
+/**
+ * A source that explicitly doesn't require traffic considerations.
+ *
+ * This typically applies for self-hosted sources.
+ */
+interface UnmeteredSource

server/src/main/kotlin/eu/kanade/tachiyomi/source/model/SManga.kt

@@ -55,6 +55,9 @@ interface SManga : Serializable {
         const val ONGOING = 1
         const val COMPLETED = 2
         const val LICENSED = 3
+        const val PUBLISHING_FINISHED = 4
+        const val CANCELLED = 5
+        const val ON_HIATUS = 6
 
         fun create(): SManga {
             return SMangaImpl()