0.6.3

• Adds setting_empty_hash_as_object setting.

0.6.1: Spyc.php fails to account for negative PHP_INT_MAX

While detecting the int type, spyc properly checks if the numerical value exceeds PHP_INT_MAX. However, it fails to account for the negative limit, so numbers less than (for example) the 64-bit limit of `-9223372036854775808` get clobbered into the limit.

0.6.0: Merge pull request #44 from tmtysk/master

Anchor and Alias test.