Converted unsigned char to char in all places

also Commented unwanted logs

	modified:   src/gecko_interface.c
	modified:   src/gecko_interface.h
	modified:   src/list.c
	modified:   src/list.h
	modified:   src/serial_core.c
	modified:   src/serial_core.h
Increased write delay to 500ms
	modified:   src/serial_core.c
	modified:   src/serial_core.h
Updated the test example file with retry timer

1. Included makefile for easy compile
2. Included timer api for retry of commands

	new file:   src/Makefile
	new file:   src/test1.c
	new file:   src/timer_api.c
	new file:   src/timer_api.h
some local  variable changed to static

	modified:   src/test1.c
Added gecko master firmware binary

	new file:   Release/Gecko Central Firmware/v2/GeckoCentral_v2_DEBUG.hex
	new file:   Release/Gecko Central Firmware/v2/README.txt