Ensure all current examples of HEC are covered

[merbla]

http://dev.splunk.com/view/event-collector/SP-CAAAFBZ

• [ ] Basic
• [ ] Batching
• [ ] Raw
• [ ] Raw Batching
• [ ] Indexer acknowledgement (see #66)
• [ ] Check acknowledgement
• [ ] Extract JSON
• [ ] Explicit JSON
• [ ] Basic authentication

[merbla]

Closing as a part of larger Serilog contrib reorg

Checkout https://github.com/serilog/serilog/issues/1627