Zend\Db Fix for #2563
Safewords should be case insensitive
Merge branch 'hotfix/db-platform-safe-words' of git://github.com/ralphschindler/zf2 into hotfix/3586

Conflicts:
	library/Zend/Db/Adapter/Platform/Mysql.php
	tests/ZendTest/Db/Adapter/Platform/MysqlTest.php
Merge branch 'hotfix/3586' into develop

Close #3586
Fixes #2563