introducing automatic purging of expired pastes, triggered by default at least 5 minutes apart, deleting a maximum of 10 pastes - resolves #3

tst/purgelimiter.php

@@ -0,0 +1,36 @@
+<?php
+class purgelimiterTest extends PHPUnit_Framework_TestCase
+{
+    private $_path;
+
+    public function setUp()
+    {
+        /* Setup Routine */
+        $this->_path = sys_get_temp_dir() . DIRECTORY_SEPARATOR . 'privatebin_data';
+        if(!is_dir($this->_path)) mkdir($this->_path);
+        purgelimiter::setPath($this->_path);
+    }
+
+    public function tearDown()
+    {
+        /* Tear Down Routine */
+        helper::rmdir($this->_path);
+    }
+
+    public function testLimit()
+    {
+        // initialize it
+        purgelimiter::canPurge();
+
+        // try setting it
+        purgelimiter::setLimit(1);
+        $this->assertEquals(false, purgelimiter::canPurge());
+        sleep(2);
+        $this->assertEquals(true, purgelimiter::canPurge());
+
+        // disable it
+        purgelimiter::setLimit(0);
+        purgelimiter::canPurge();
+        $this->assertEquals(true, purgelimiter::canPurge());
+    }
+}