Add a notes about non-blocking receives.
Add a notes about non-blocking receives.

ChernyshovYuriy/openxc-android,mray19027/openxc-android,dhootha/openxc-android,msowka/openxc-android,prateeknitish391/demo,openxc/openxc-android,dhootha/openxc-android,petemaclellan/openxc-android,openxc/openxc-android,msowka/openxc-android,mray19027/openxc-android,prateeknitish391/demo,prateeknitish391/demo,ChernyshovYuriy/openxc-android,petemaclellan/openxc-android