1.Add txtSource
2.let the content continuly
3.will not find crash

Signed-off-by: chuzhoux <chux.zhou@intel.com>
Merge https://github.com/jzy09/txtReader
Merge https://github.com/jzy09/txtReader
Merge https://github.com/jzy09/txtReader
1. Change app icon
2. fix bug : the crash in adding backward page when it is in the first page