1.0.1
 - Removed unnecessary methods from common driver
 - Added new tests and code coverage

1.0.0
 - Signature of all constructors was unified
 - Method "load" now accepts arguments to set lock for entry key when cache is expired
 - Entries now never expires instead when cache entry expired library returns expired data and attempts to generate new data
 - Temporarily removed PDO and MongoDB drivers
 - Added driver for APC (http://php.net/apc)
 - Autoloading was changed to PSR-4
 - New tests

0.2
 - No need to remove deleted keys from tags
 - Driver for \Memcached.
