Added software spi stuff

examples/softwarespi.php

@@ -0,0 +1,25 @@
+<?php
+
+require_once __DIR__."/../vendor/autoload.php";
+require_once __DIR__."/GLOBALS.php";
+
+use NoccyLabs\Gpio\Gpio;
+use NoccyLabs\Gpio\GpioTickHandler;
+use NoccyLabs\Gpio\Bus\SoftwareSpiBus as SPI;
+use NoccyLabs\Crap\Dumper;
+
+$gpio = new Gpio(true);
+
+// create spi bus
+$spi = new SPI();
+// bind the spi pins
+$spi->sclk = $gpio[1];
+$spi->mosi = $gpio[2];
+$spi->miso = $gpio[3];
+// write to the spi bus
+$spi->write("\xBE\xEF");
+// read the two bytes exchanged with the write()
+$read = $spi->read(2);
+
+// 
+Dumper::dump($read);