example v1.6 and class DlReader v1.6

- in ComProtocol.portWrite() from this version we use an nonblocking write() overloaded method from the FTDI class and we have implemented retry count (Consts.MAX_COMMUNICATION_BREAK_RETRIES times) on communication break. If the number of the communication break retries exceeded, raised DlReaderException have Consts.DL_READER_IS_NOT_CONNECTED err_code and usb device is closed. This algorithm solve usb otg device disconnect detection problem on the Runbo X5 and probably some other Android smart phones with usb otg port.

git-svn-id: svn://192.168.1.162/sw_open/ufr/android/examples/trunk/block_read@57 bc32c577-c6d7-4b02-862b-52b34d7f137c