Bulk (mostly documentation) update

 - Remove PHP version from license notices
 - Bump year number in copyright notices
 - Recommend PHP 5.4 or newer to be used
 - Tell Travis-CI to test on PHP 5.3.0 instead of the latest 5.3 version

Related: #3450
diff --git a/system/language/english/migration_lang.php b/system/language/english/migration_lang.php
index 66ce456..9dbff7a 100644
--- a/system/language/english/migration_lang.php
+++ b/system/language/english/migration_lang.php
@@ -2,11 +2,11 @@
 /**
  * CodeIgniter
  *
- * An open source application development framework for PHP 5.2.4 or newer
+ * An open source application development framework for PHP
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014, British Columbia Institute of Technology
+ * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
- * @copyright	Copyright (c) 2014, British Columbia Institute of Technology (http://bcit.ca/)
+ * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	http://codeigniter.com
  * @since	Version 3.0.0
@@ -37,14 +37,14 @@
  */
 defined('BASEPATH') OR exit('No direct script access allowed');
 
-$lang['migration_none_found']		= 'No migrations were found.';
-$lang['migration_not_found']		= 'No migration could be found with the version number: %s.';
-$lang['migration_sequence_gap']		= 'There is a gap in the migration sequence near version number: %s.';
-$lang['migration_multiple_version']	= 'There are multiple migrations with the same version number: %s.';
-$lang['migration_class_doesnt_exist']	= 'The migration class "%s" could not be found.';
-$lang['migration_missing_up_method']	= 'The migration class "%s" is missing an "up" method.';
-$lang['migration_missing_down_method']	= 'The migration class "%s" is missing a "down" method.';
-$lang['migration_invalid_filename']	= 'Migration "%s" has an invalid filename.';
+$lang['migration_none_found'] = 'No migrations were found.';
+$lang['migration_not_found'] = 'No migration could be found with the version number: %s.';
+$lang['migration_sequence_gap'] = 'There is a gap in the migration sequence near version number: %s.';
+$lang['migration_multiple_version'] = 'There are multiple migrations with the same version number: %s.';
+$lang['migration_class_doesnt_exist'] = 'The migration class "%s" could not be found.';
+$lang['migration_missing_up_method'] = 'The migration class "%s" is missing an "up" method.';
+$lang['migration_missing_down_method'] = 'The migration class "%s" is missing a "down" method.';
+$lang['migration_invalid_filename'] = 'Migration "%s" has an invalid filename.';
 
 /* End of file migration_lang.php */
 /* Location: ./system/language/english/migration_lang.php */
\ No newline at end of file