[NFR] Database session save handler

[niden]

DB session save handler - it would be cool if besides file adapter a db adapter would exists. Once again, it can be solved through session_set_save_handle but it would be so much cooler if Phalcon would handle it internally.

The adapter should be able to work with PHQL and thus with any backend supported by the Phalcon\Db

[mrspartak]

It would very cool.
But in our age, the rightest way is to make noSQL adapter, such as Redis to store the Sessions.

[niden]

With 0.7 we will have interfaces on all components. Therefore anyone can
implement session handlers to save to any database or storage medium. Redis
of course is a popular one. I don't know if this will become part of the
framework in the very near future, but user implementations in PHP can
definitely do the job until it becomes.

[phalcon]

This is currently addressed in the incubator https://github.com/phalcon/incubator/tree/master/Library/Phalcon/Session/Adapter