Merge pull request #716 from sjinks/xcache

[NFR] Add XCache Cache Backend
Reviewing Xcache, fixes to events in dispatcher, fixes in Paginator\QueryBuilder, adding examples
Merging changes, Regenerating build 32bits [ci skip]
Regenerating build 64bits [ci skip]
Avoiding escaping already escaped strings in PHQL
Merge branch '1.2.0' of https://github.com/phalcon/cphalcon into 1.2.0
Added Phalcon\Cache\Frontend\Igbinary
Updated email address
Add -fvisibility=hidden and optionally -flto if they are supported
Draft version
Use native iterators instead of userspace ones
Added missing TSRMLS_CC
Merge pull request #721 from sjinks/opt-build

Allow gcc to better optimize the code
More efficient removal of _PHCA prefix
Merge pull request #720 from sjinks/igbinary

[NFR] Support igbinary as a cache frontend
Docblocks typos [ci skip]
Using fast increment where available [ci skip]
Regenerating build 64bits [ci skip]
Marking const some internal functions, adding clear function to forms elements, improving docblocks, other minor fixes
Merge branch '1.2.0' of https://github.com/phalcon/cphalcon into 1.2.0