Empty message condition
Revert "Empty message condition"

This reverts commit c05ec1169d6365a7237581969ae535c7375c632f.
Cleaning methods descriptions
Merge origin/2.0.0 into 2.0.0
Correct names of used classes
Collection readattribute
Fix bug #1706
Merge pull request #1705 from mruz/2.0.0

Correct names of used classes
PHP empty() instead of zephir empty
Validation improvement
Merge pull request #1732 from mruz/2.0.0

Validation improvement
Compiling with 'empty' operator [ci skip]
Merge remote-tracking branch 'phalcon/2.0.0' into nfr_1679