Merge pull request #161 from methane/master

Use PyPy-2.1 on Travis
Use 'replace' error handler (Fixes #125)
Merge branch 'master' of github.com:PyMySQL/PyMySQL
Use range_type instead of range.
Minor spelling & grammar corrections in docstring.
Remove unnecessary list creation.
Add tests for nextset
Fix cur.nextset() doesn't works.
Fix warning_count is not int.
Add multi cursor test currently failed.
Add comment about SScursor and nextset.
Merge pull request #162 from methane/fix-nextset

Fix nextset
Remove errorhandler and related code.
Remove unnecessary tuple(rows) conversion.
More accurate cursor.nextset()
Merge pull request #163 from methane/remove-errorhandler

Remove errorhandler
Fix cyclic reference Connection <-> MySQLPacket
Remove unused variable.