Factory updates

• Added 'skip_on_failure` for the chain factory
• Added 'persistent_id ` for the memcached factory

General bugfixes, validation of chain factory and alias option

Merge pull request #33 from andrey1s/aliases

add configuration aliases

Adding service definition

Merge pull request #28 from aequasi/master

Forgot to add service definition

Fixing static calls

Merge pull request #27 from aequasi/master

Fixing static calls

Adding Chain Adapter factory

Merge pull request #25 from aequasi/master

Adding chain factory, and allowing options to just be an indexed arra…

Adding DSN for Mongo and Redis

Merge pull request #24 from aequasi/master

Allowing use of DSN for redis and mongo factories

Added memcache factory

Merge pull request #21 from php-cache/Nyholm-patch-1

typo

Added MongoDB factory

Merge pull request #20 from php-cache/mongodb

Mongodb factory

Bugfixes, readme update and added doctrine filesystem factory

Merge pull request #19 from php-cache/bugfix2

Better option validation for filesystem

First release

Merge pull request #14 from Nyholm/doctrine

Added doctrine factories