This is not finished.

cleanup(hash_func): std::pair<str,str> has its own hash func

enh(cbwd): new logger

Extcommand

reserve() does not set exactly the capacity but at less this one.
Nevertheless, it can be greater, this made the tests to fail.

* enh(storage): We get the table columns max size.

This is done for:
* acknowledgements
* customvariables
* comments
* custom_variable_status
* event_handlers
* downtimes
* host_dependencies
* host_check
* host_groups
* and others...

Extcommand

enh(cmake): build with ninja fixed.

This reverts commit 7c47be9c.