Add USART library and some SIM900 test
Update .gitignore
Change sim900 to sim900a, and add dial function.
Remove LCD task.
Add SIM900A_GetModule.
Add SIM900A_Answer. Used for answer the phone.
Update to sim5320E.
Merge branch 'sim900'

Conflicts:
	FreeRTOS/main-ugfx.c