Release 1.5.0

• Issue #20 Refactor handling of stdin/stdou/sterr streams with proc_open(). By default these streams now operate in non-blocking mode which should fix many hanging issues that were caused when the command received/sent a lot of input/output. This is the new default on Non-Windows systems (it's not supported on Windows, though). To get the old behavior the nonBlockingMode option can be set to false.