Zend\Db\Sql Select Subselect Bugfixes:
* Select Joins should share state when processing subselect
* Decorators should be propagated down into subselects
Fix unused imports
Remove unused variables
Add test case for constructor method
Prevent ArrayObject recursion in 5.6
Merge branch 'hotfix/#6096-prevent-php-5.6-arrayobject-infinite-recursion'

Close #6096
Merge branch 'hotfix/#6093-dead-code-cleanups'

Close #6093
fixed typos
Merge branch 'hotfix/#6116-typo-fixes'

Close #6116
Zend\Filter\Compress\Tar::setMode() should work with case-insensitive - fix #6102
fix for CS at tests/ZendTest/Filter/Compress/TarTest.php
Merge branch 'hotfix/#6103-#6102-tar-compress-filter-mode-case-insensitive'

Close #6103 #6102
Merge pull request #5392 from ralphschindler/hotfix/db-subselect-for-joins-sharing-process-state

Zend Db: Multiple nested selects - Zend Paginator with nested select bind parameters error
Merge branch 'hotfix/5392'

Close #5392