Adds function of setting font, and re-adds simple function of autoshutdown.
新增设置字体功能，恢复简单的自动关机功能。
2
This machine has a 2 hours autoshutdown function, if need continue to work just press the switch once again.
本机设有2小时自动关机功能，自动关机后如需继续工作只需重按开关一次便可。
3
On OS6 (Bold 9700) the camera in the app does not autoshutdown after taking a photo, I have to click the back arrow, which take me back to the form, and the photo is still taken as expected.