adding transparent background support to barcode
removing alpha as it's not used
#5465 use strlen instead of empty
#5465 unit test
#5465 added link to github issue
Specify correct return type for `Pdo\Connection::getLastGeneratedValue`

See http://php.net/manual/en/pdo.lastinsertid.php for reference that it returns `sting` instead of `int`.

TODO: change type of `$lastInsertValue` property and `getLastInsertValue` method in `Zend/Db/TableGateway/AbstractTableGateway.php` accordingly.
[http] Fix a couple of tests
[http] Enable online tests in Travis-CI
[http] More fixes
Fixes #5516
- adds fix into Zend\Mvc\Router\Http\Segment::encode
- adds test case for new fix
Fixes #5516
- fixes cs in test case
Added a test to show the duplication of routes when using a chain_link and the scheme route type.
update userguide manual link
Change hardcoded events names by its constant.
shortcircuit rendering if no messages
shortcircuit rendering if no messages

fix git editor whitespace
More explicit name for requested name
consistent naming
remove unneeded createService functions because actually do same with base class
FIX Zend\Db\Sql\Select: getRawState('order') is inconsistent after
calling reset() #5767