Force memcache delete 2nd arg to 0
Remove lib_options in favor of get/set compress threshold options
Merge pull request #5633
Merge pull request #5633 in develop
Merge pull request #5633 in master
Merge branch 'develop' of github.com:zendframework/zf2 into fieldset-allowed-object-class
Merge pull request #5755
Merge pull request #5755 in develop
Merge pull request #5755 in master
Merge pull request #5762
Merge pull request #5762 in develop
Merge pull request #5762 in master
Merge pull request #5714
Merge pull request #5714 in develop
Merge pull request #5714 in master
Merge pull request #5551. Fix #5549
Merge pull request #5551. Fix #5549 in develop
Merge pull request #5551. Fix #5549 in master
Merge pull request #5726 from franz-deleon/feature/arrayutils_merge

ArrayUtils:merge() replaced array_key_exists() to isset() for performance
Enabling the Request object to generate the correct scheme for SSL URI requests to
a webserver through an HTTP proxy or load balance

HTTP_X_FORWARDED_PROTO request header is sent by loadbalancers insted of HTTPS to
indicate the URI was requested via a secure connection.

An example of this useage is Amazon Elastic Beanstalk applications which can sit
behind a load balancer (when autoscaling)