SEC-2119: Add a 'form-parameter' attribute to <remember-me>

This change extends the namespace configuration of <remember-me>
with a 'form-parameter' attribute. The introduced attribute sets
the 'parameter' property of  AbstractRememberMeServices.

This enables overriding the default value of
'_spring_security_remember_me' using the namespace configuration.

core/src/test/java/org/springframework/security/authentication/jaas/memory/InMemoryConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010 the original author or authors.
+ * Copyright 2010-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.