Merge pull request #114 from endeveit/master

Simplification of Phalcon\Cache\Frontend\Msgpack
fix undefined variable in Phalcon\Session\Adapter\Memcache
removed $success return value from trauncateTable method. returning value from "TRUNCATE TABLE" query operation was causing code to hang on some tables
changed truncateTable method to use execute instead of query according to phalcon api (execute should be used for queries that do not return rows)
Revert "removed $success return value from trauncateTable method. returning value from "TRUNCATE TABLE" query operation was causing code to hang on some tables", problem was user error :)

This reverts commit 1d9c2e0d6f88804717d55af32acfa7a813bbc7c9.

Conflicts:
	Library/Phalcon/Test/ModelTestCase.php
altered ModelTestCase::truncateTable method to use execute() instead of query()
Merge pull request #118 from digitronac/master

changed from query() to execute() in ModelTestCase,  reverted closed pull request #117 (user error! =] )
Merge pull request #116 from PyYoshi/fix_Session.Adapter.Memcache_error

fix undefined variable in Phalcon\Session\Adapter\Memcache
Merge remote-tracking branch 'upstream/master'
Deletes memcache cache backend because it is already exists in Phalcon #115