Add PR #493 and Blosc-1.11.1 to release notes.
Add PR #493 and Blosc-1.11.1 to release notes.

PR #493: single codebase Python 2/3

PyTables/PyTables,avalentino/PyTables,FrancescAlted/PyTables,PyTables/PyTables,PyTables/PyTables,FrancescAlted/PyTables,FrancescAlted/PyTables,avalentino/PyTables,avalentino/PyTables