Added ZUtil.convertDataToLatin1 and ZUtil.convertLatin1ToData
Move logic to convert QByteArray to and from encoded data strings to ZMQ_Util static methods
Make ZMQ_Helper's send_string and recv_string use ZMQ_Util's data encoding methods
Revise format of encode_decode test
Added ZMQ_Helper#send_bytes and #recv_bytes (as backend to #send_string and #recv_string)
Make ps_send use send_bytes_array and recv_bytes_array to cut down on sending overhead

--HG--
extra : amend_source : 915a6cdbae74c2c799e6d498b2204975462a00e5
Make ps_action and ps_kill receiver loops use bytes instead of strings to reduce overhead and possibility for misunderstanding a string's encoding
Change some uses of char* to const char*
Some reformatting in zmq_helper.h