Allow APC Adapter to use specific key and TTL

Along with other APC adapters (metadata, cache\backend), the use of prefix and TTL would allow cache purge without purging all APC cache.
Using latest Zephir
Using latest Phalcon, fixing incompatibilities with 'empty' operator
Using latest Zephir
Using latest Zephir
Fix #3055
added documentation to Phalcon\Events\Event
Merge pull request #3059 from skollro/2.0.0

added documentation to Phalcon\Events\Event
Using latest Zephir
Clarify that in Between and StringLength checking is inclusive
Merge pull request #3057 from dreamsxin/3055

Fix #3055
Merge pull request #3054 from dugwood/patch-1

Allow APC Adapter to use specific key and TTL
Merge pull request #3051 from phresnel/2.0.0

2.0.0
Coding style fixes