* Make dialogs responsive for mobile devices
* Support mouse backward/forward buttons
* Use back icon to close layer 2 components on mobile devices
Currently layer 2 components are: 1. sidebar 2. notebook 3. dialogs
They are all fullscreen on mobile devices.
* Add translations
* Fix excerpts cannot be deleted in Chrome browsers
* Show book details in reader sidebar
* Set minimum search term length to 1 for CJK languages
* Use more system fonts as custom fonts, closes#31
Huang Xin