* [Feature] Removed the useless attribute compatibility check in smget.
* [Feature] Forced btree overflow action for temporary use.
* [Feature] Automatic srcub stale when a new node is added.
* [Feature] Proxy support where memcached operates as a backend of it.
* [Feature] Added "cmd_cas" memcached stat and activated cas stats.
* [Feature] Increased MAX_SERVICECODE_LENGTH. 32 => 128.
* [Feature] Added MAX_HOSTNAME_LENGTH whose value is 128.
* [Fix] Slab free_small_space overflow.
* [Fix] TCP port bug when UDP port of 0 is only specified.
* [Fix] Disabled UDP by default.
* [Fix] Incorrect value length checking of collection.
* [Enhance] Handled multiple scattered values of an item or an element.
* [Enhance] Used mblocks for command parsing and tokenizing.
* [Test] Reorganized the unit tests.
* [Test] Fixed the intermittent failure in the testapp test.
* [Other] A lot of code refactoring.
