Autoscroll to the last chapter

Currently uses the last chapter loaded, not the last chapter on screen, so may not be 100% accurate.
Resolves issue #7.

app/src/main/java/org/bspeice/minimalbible/activity/viewer/BibleViewerPreferences.java

@@ -17,4 +17,8 @@ public interface BibleViewerPreferences {
     int baseTextSize();
 
     void baseTextSize(int baseTextSize);
+
+    int currentChapter();
+
+    void currentChapter(int currentChapter);
 }

app/src/main/kotlin/org/bspeice/minimalbible/activity/viewer/BibleView.kt

@@ -39,6 +39,7 @@ class BibleView(val ctx: Context, val attrs: AttributeSet) : LinearLayout(ctx, a
         val adapter = BookAdapter(b, prefs)
         adapter.bindScrollHandler(scrollPublisher, layoutManager)
         bibleContent setAdapter adapter
+        bibleContent scrollToPosition prefs.currentChapter()
     }
 }
 
@@ -110,8 +111,10 @@ class BookAdapter(val b: Book, val prefs: BibleViewerPreferences)
     /**
      * Bind an existing view to its chapter content
      */
-    override fun onBindViewHolder(view: PassageView, position: Int) =
-            view bind chapterList[position]
+    override fun onBindViewHolder(view: PassageView, position: Int) {
+        prefs.currentChapter(position)
+        return view bind chapterList[position]
+    }
 
     /**
      * Get the number of chapters in the book