set data with check (issue #11)

This version introduces multiple enhancements:

allow to set some special rules to check data with regular expression before add to object

Details of additions/deletions below:
--------------------------------------------------------------

Added:      examples/base_object/data_validation.php
            -- Added --
                data validation example

Modified:   Base/BlueObject.php
            -- Added --
                $_validationRules list of rules to check
                _validateDataKey search validation rule for given key and check data
                _validateData check data with given rule and set error information
                putValidationRule set regular expression for key find and validate data
                destroyValidationRule remove validation rule from list
                returnValidationRule return validation rule or all rules set in object
            -- Updated --
                _putData check data with validation, skip data if its invalid

Modified:   examples/base_object.php
            -- Added --
                data validation example