allow string/char etc for config (#117)

fix conf loaded (memory leak/corrupt msg on bad cfg) (#115)

Add clarity on config settings in reference doc.

Fixed:

An error from the following could have the error string corrupted & produced a small memory leak:
* .kfk.Consumer due to bad config or unable to create
* .kfk.Producer due to bad config or unable to create
* .kfk.Topic due to bad config

Small memory leak on each successful call to .kfk.Consumer,.kfk.Producer,.kfk.Topic.

Callbacks now work on bad config. (#102)

Also removed invalid fetch.wait.max.ms for producers

wrapper for rd_kafka_query_watermark_offsets. Ref #94

Handle sym list in cfg values (#93)

Update comments for Subscribe/Assign funcs (#92)

Update to AssignOffsets function to avoid purge of current assignment (…

…#74)

* Addition of support for AssignOffsets function to augment or modify a current list of assignments

* Update to add additional checking for calls to AssignOffsets with items that already exist or do not

* update to reflect requested change for removing current assignment

Co-authored-by: Conor McCarthy <[email protected]>
Co-authored-by: mshimizu-kx <[email protected]>
Co-authored-by: Conor McCarthy <[email protected]>

Merge pull request #20 from KxSystems/dev

Subscriptions to multiple topics from a single client

Merge pull request #18 from cmccarthy1/dev

Additional functionality and type checking update

Merge pull request #16 from cmccarthy1/master

Addition of Window build for Kafka interface