Move wisski instance code to separate package

internal/wisski/php/server.php

@@ -0,0 +1,34 @@
+<?php
+
+// This file contains code to execute a php execution server.
+// It is passed as a *command line literal * directly to 'drush:script'.
+//
+// As such it is preprocessed and shortened.
+// It should only contain comments at the beginning of each line, and only starting with '//'.
+// See wisski_php_server.go.
+
+// don't buffer stdin!
+stream_set_read_buffer(STDIN,0);
+
+// stop all other output
+ob_start(null,0,PHP_OUTPUT_HANDLER_CLEANABLE);
+
+while($line =  fgets(STDIN)){
+    // decode the command to run
+	$code=@json_decode($line);
+
+    // execute it
+	try{
+		$json = json_encode([eval($code),""]);
+	}catch(Throwable $t){
+		$json = json_encode([null,(string)$t]);
+	}
+	if($json===false) {
+		$json = '[null,"Error encoding result"]';
+	}
+
+    // and write out the result
+	ob_end_clean();
+	fwrite(STDOUT,"$json\n");
+    ob_start(null,0,PHP_OUTPUT_HANDLER_CLEANABLE);
+}