arm64 support

[qimingxingyuliyang]

Description

cann't build on arm64 mechine. without about this "X11/keysym.h" ...

[falsechicken]

So does "android and ios" support mean arm? There are other operating systems that run on arm lol. I am trying to cross compile from Linux x64 to Arm/64 but get:

GOOS=linux GOARCH=arm go build . 

# github.com/go-vgo/robotgo
../../../github.com/go-vgo/robotgo/hook.go:30:24: undefined: hook.Event
../../../github.com/go-vgo/robotgo/hook.go:31:9: undefined: hook.Start
../../../github.com/go-vgo/robotgo/hook.go:36:2: undefined: hook.End
../../../github.com/go-vgo/robotgo/hook.go:41:19: undefined: hook.Event
../../../github.com/go-vgo/robotgo/hook.go:42:9: undefined: hook.Start
../../../github.com/go-vgo/robotgo/hook.go:47:2: undefined: hook.End
../../../github.com/go-vgo/robotgo/hook.go:52:2: undefined: hook.StopEvent
../../../github.com/go-vgo/robotgo/hook.go:56:31: undefined: hook.Event
../../../github.com/go-vgo/robotgo/hook.go:57:9: undefined: hook.Process
../../../github.com/go-vgo/robotgo/hook.go:61:64: undefined: hook.Event
../../../github.com/go-vgo/robotgo/hook.go:57:9: too many errors

[pokitpeng]

please enable CGO GOOS=linux GOARCH=arm CGO_ENABLED=1 go build .

[vcaesar]

Now, there is supported: Mac, Linux and Windows (Needing libpng.a).