RFR: JDK-8067955 DIO privileges issue

[Sergey Nazarkin]

issue: http://cr.openjdk.java.net/~snazarki/8067955/
webrev:  https://bugs.openjdk.java.net/browse/JDK-8067955

This is intermediate patch to resolve DIO privilege issue. A list of 
required java permissions and udev script for gpio pins access are 
included.   This files are just examples since manual installation is 
required and udev script may be incompatible with some platform (e.g. 
Ubuntu on Freescale imx6)

-- 
/Sergey