Some fixes

* more info displayed when cannot connect to database
* added Cache:delete($key) function
* added support for OTHire 0.0.3
* deleted unused ODBC and PostgreSQL files
* fixed support for Gesior layouts

system/libs/cache_xcache.php

@@ -47,6 +47,10 @@ class Cache_XCache
 		return true;
 	}
 
+	public function delete($key) {
+		xcache_unset($key);
+	}
+
 	public function enabled() {
 		return $this->enabled;
 	}