add an enum to manage Leds
Allow to specify Led for fadeToColor command

add a new method to Blink
fadeToColor(RGBColor color, int fadeTime, BlinkLeds led) : the fading will only occurs on leds specify by led (ALL_LEDS, LED_1 or LED_2)
Allow to specify Led for fadeToColor command

add a new method to Blink
setColor(RGBColor color, int fadeTime, BlinkLeds led) : the color will be set only for the leds specified by led (ALL_LEDS, LED_1 or LED_2)
Make Led specification mandatory in SetColor fadeToColor Commands

these calls (whitout specifying the led) were no more used by Blink.
Rename WriteCommand into ChangeLedColorCommand

and manage directly into ChangeLedColor mechanism for Color and Led specification.
So that they are no more duplicated in SetColorCommand and FadeToColorCommand
Move all command classes in a dedicated command package
Rename BlinkLeds into BlinkLed
Improme readme: add details of implemented methods on Blink
Merge pull request #1 from avernois/choose_leds

Choose leds