Omniduct

Features and Enhancements:
- Added warning when users push dataframes using `HiveServer2Client.push` when default table properties are implicitly used.

Bugfixes:
- Fix reference to `self.remote` in WebHdfsClient constructor, which causes the client to be prepared at creation time rather than lazily deferred until first use.
- Fix empty StringIO buffer being returned when opening a non-existent file with mode 'r'.

Features and enhancements:
- Allow all `host` specifications provided to a `Duct` instance to include the port. This port will take precedence over any value supplied via `port`.
- Supplying a list of hostnames to a `Duct` instance as the `host` value will result in naive load-balancing (i.e. the hostnames will be randomly sorted and the first accessible hostname/port will be chosen).
- Added support for automatically configuring `WebHdfsClient` instances via a cloudera XML configuration file.

Bugfixes:
- Fix typo/bug in `LocalFsClient.open()` due to missing `self` reference in function definition.

This release marks the graduation of omniduct from a fledgeling project to a publicly supported body of code. Core functionality is now fully documented. Refer to documentation for a full rundown of functionality.