Adding the ability to run php-r on Windows

[jackpolifka]

I tried the old library on a PHP 5.5.12 / Windows 7 setup and a PHP 5.4.12 /Windows 8 setup.When the library would call the stream_set_blocking() method in CommandLineRProcess.php it always return false resulting in PHP to hang when fgets was called in the following line. After reading http://php.net/manual/en/function.stream-set-blocking.php and https://bugs.php.net, it seems that stream_set_blocking() had a problems on Windows machines for a while.

To get around stream_set_blocking(), I had errors written to a file instead of reading them from a pipe.

[kachkaev]

Thank you for this pull request! I'll try to have a look at it in a few days.

[jackpolifka]

I merged the updates from master into my fork of php-r and now hangs from my quick test. That in addition to the errors reported in the issue #7 in combination with my lack of time currently, I'm going to close this pull request.

[kachkaev]

OK. It's good that you've written that code anyway @jackdp, because I'm sure there will be useful. I hope someone will find out how to add to it and finally make the things working in Windows!