增加刷新，修复切换章节 (#4784)

* 调整页脚章节标题位置

* 修复章节切换问题

* 增加刷新

* 调整屏幕滚动问题

* ...

* 修复图片过长滚动问题

* ...

app/src/main/res/values/strings.xml

@@ -829,7 +829,6 @@
     <string name="import_bookshelf">Import the list of books</string>
     <string name="pre_download">Download in advance</string>
     <string name="pre_download_m">Pre-download %s pages</string>
-    <string name="single_page_scroller">Single Page Scroller</string>
     <string name="pre_download_s">Download %s chapters in advance</string>
     <string name="is_enabled">Is enabled</string>
     <string name="background_image">Background image</string>