memcached_server_by_key actually returns a memcached_server_instance_st instead
of memcached_server_st. The structures were compatible to eachother, but this
recently changed between 1.0.5 and 1.0.13.

See https://bugs.launchpad.net/libmemcached/+bug/1076048 for more info.
Added 4 functions to further debug issues and error codes in a multi-server environment:

	getLastErrorMessage()
	getLastErrorCode()
	getLastErrorErrno()
	getLastDisconnectedServer()
Added MEMCACHED_BEHAVIOR_DEAD_TIMEOUT class constant 'OPT_DEAD_TIMEOUT' (new in 1.0.3)
report about SASL support
php_memcached.c added connect timeout variable
php_memcached.h added connect timeout
php_memcached_session.c added connect timeout
memcached.ini added connect timeout
Add missing memcached.use_sasl ini option to doc.
Add in missing setSaslAuthData to api doc.
Add notes on building to README.
Warn if trying to use SASL when memcached.use_sasl is off.

Without this, a far less helpful error message from the underlying
libmemcached library would be reported.
Removed memcached.sess_consistent_hashing option.

1. Removed memcached.sess_consistent_hashing which is a lesser version  of memcached.sess_consistent_hash
2. Added default value for memcached.sess_consistent_hash
Merge pull request #52 from memcachier/saslwarn

Warn if trying to use SASL when memcached.use_sasl is off.
Merge pull request #43 from remicollet/issue-infosasl

report about SASL support
Merge pull request #50 from memcachier/readme

Add notes on building to README.
Removed unused memcached.ini option

After the merge of commits 5ff9516240 and faf84af789
the memcached.sess_num_replicas option is no longer used
Merge pull request #49 from memcachier/doc

Document SASL support
Merge pull request #64 from Vendini/Remove_ini_option

Removed unused memcached.ini option
Merge pull request #42 from poison/master

Fixed getServerByKey function