Merge branch 'hotfix/#6877-zend-session-event-manager-dependency'

Close #6877
Close #6818
Merge branch 'hotfix/#6871-memcache-return-false-on-failure-perf-improvement'

Close #6871
Merge branch 'hotfix/#6778-zendxml-suggestion-in-zend-json'

Close #6778
Return the text value in _ array key

If element has attributes & string value until now the string value was ignored & lost, I added the _ index so that it also returns the string value along with the attribute names
Fix CS + reduce branch depth
Reproducing test case for #6279
#6279 - #6879 - minor CS fixes
Merge branch 'hotfix/#6279-#6879-zend-config-reader-xml-node-value-conflict' into develop

Close #6279
Close #6879
Forward port #6279
Forward port #6879