Log Message:
Update 0.54 to 0.60
-------------------
0.60  Sun Oct 20 12:24:09 2013
    - use Lexical::SealRequireHints to fix %^H bugs
    - rename my_hints -> hints (my_hints is still supported, but deprecated)
    - update ppport.h from 3.19 to 3.20
    - code cleanup