Fix notices when phalcon.orm.column_renaming is 0

Close #1801
Test case for #1801
Updated CHANGELOG
Implement reset() for metadata adapters other than memory

Close #1934
Updated CHANGELOG
Bug fix for PHP 5.3 and 5.4
Use phalcon_prepare_virtual_path_ex()
Merge pull request #1952 from sjinks/issue-1934

Fix notices when phalcon.orm.column_renaming is 0 and implement reset() for metadata adapters