bigcouch errors

this is a parent task for all bigcouch errors we encounter

(from redmine: created on 2014-01-06, relates #4939 (closed), relates soledad#5011 (closed), relates soledad#5023 (closed), relates soledad#5024 (closed), relates #4983 (closed), relates soledad#5076 (closed), relates soledad#5256 (closed))