Conflicts:
	doc/sphinx/book/connectors/__c.rst

Verified and updated all instructions and code examples for tarantool-c.

* Switch to YAML instead of JSON
* Add utilites for replication
* Print test-run internal errors to console

Fill IPROTO_KEY for DELETE and IPROTO_TUPLE for INSERT/REPLACE.

- Update link to configuration files
- Change number of queries and data set size
[skip ci]

Delete the previous checkpoint in sophia only if we have a new one.

Actually fix the bug and add a test case.