Bulk update: Fixing session PUT (in handler,y), EL v8 compatibility, python 3 based with enhanced code debugging. (#131)

* Update yaml default load second argument yaml.Loader;
Refactor: In handler.py method traceback and use in exception;
Add print statements (as debug hints) in session,py and other modules;
Fix in handler.py by removing bucket (which is no key, value
pair) from setting into session headers as argument for start_response call);
Add __init__py in plugins folder to allow import from makeAccount.py and
remove local KibbleDatabase class there;
Make in database.py *Wrapper classes private;
Add into kibble.yaml configuration key elasticsearch versionHint
(by default 8) to allow for more robust and transparent initialization;
Refactor in setup.py into methods makeIndices and makeAccount();
Fix check for undefined snap in kibble.v1.js.
Improvement: Evaluate result in makeAccount.py;
Remove cgi import (not used) and deprecated since py 3.11;
Use __debug__ to print out more debugging information;
Set cookie httpOnly;
Update setup docs (tested with python 3.9.1 and 3.13.0).

* New _KibbleESWrapperEight class inheriting fro ..Seven using Nestedicts to replace interval with calendar_interval in body lists.
See https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-datehistogram-aggregation.html#calendar_and_fixed_intervals
Fix NPE err.message in handler.py and use traceback_output (needs more filtering to not expose stacktraces pathes)

* Fixed: Removed overriding scroll method in ..Eight class as no body argument is never set