fix NoTypeCheckingTest
add EX, PX, NX, XX flags for SET command with tests
fix test issue with existing keys #19
Release 0.9 to Pypi. Now fully backwards compatible.

- `get_next_published` was renamed to `next_published`
- `get_as_list/set/dict` were renamed to `aslist/asset/asdict`
- API change for LUA script execution, but support for complex return
  types instead.
Bug fix in examples: 'next_published'
Merge pull request #19 from tumb1er/extended_set_syntax

EX, PX, NX, XX flags for SET command
Some improvements to the extended set() operations. Renamed parameters for clarity and using encode_int.
Merge pull request #18 from tumb1er/no_type_checking_test

fix NoTypeCheckingTest
Improved enable_typechecking in unit test.
Improved 'get()' documentation.
Release 0.10 on pypi.