Log Message:
update to 2.1.0.

changes since 2.0.1:

2.1.0
- Servers may be flagged up/down and the user may specify a error
  callback
- Individual server params and up/down status may be changed at
  runtime
- New methods: setServerParams(), getServerStatus()
- Statistics methods support fetching other kinds of stats (slabs,
  items, cachedump, ...)
- Fixed PECL bugs #7631, #8117 (erroneous line feeds in config.m4)
- Added memcache.max_failover_attempts ini directive, which can be
  used to configure max number of servers to try when setting and
  getting data.

2.0.4
- Redefined retry_interval as long to fix no-automatic-reconnect
  behaviour
- Fixed PECL bugs #7635, #7637 (OnUpdateInt: referenced symbol not
  found)

2.0.3
- Display ini entries in phpinfo() output
- Fixed Zend2 compat

2.0.2
- Added "memcache.default_port" ini directive (default 11211)
- Added "memcache.allow_failover" ini directive (default On)
- Added "memcache.chunk_size" ini directive (default 8192 bytes)
- Setting retry_interval parameter to -1 disables automatic reconnect
- Fixed PECL bug #7331 (NULL pointer freeing causes memcache to
  segfault)