Upgrade to HikariCP 2.2.5

Closes gh-1897
Restore compatibility with Jetty 8 when SSL is being used

ServerConnector is in different packages in Jetty 8 and Jetty 9 which
was leading to a NoClassDefFounderError when SSL was used with
Jetty 8.

This commit updates SslServerConnectorFactory to return an
AbstractConnector, a super class of ServerConnector, that is in the
same package in both Jetty 8 and Jetty 9. This class does not provide
a setPort method so the setting of the port has been pushed down into
the SslServerConnectorFactory implementation.

SSL samples for both Jetty 8 and Jetty 9 have been added to verify
SSL with both supported versions of Jetty.

Closes gh-1925
Polish
Add 'module' repacker layout

Add a 'module' layout for the repackager which includes all 'compile'
and 'runtime' scope dependencies and does not require a main class.

Fixes gh-1941
Allow servlet context parmeters to be configured via declaratively

Previously, configuration of a ServletContext init parameter required
the use of a ServletContextInitializer bean. This commmit adds
support for declarative configuration via the environment using
server.context_parameters.<name>=<value>.

Closes gh-1791
Use embedded docbook XSLT files

Switch from external docbook XSLT to those shipped as part of the
Maven plugin.

Fixes gh-1942
Merge branch '1.1.x'
Find @ConfigurationProperties annotation on proxy

Update ConfigurationPropertiesReportEndpoint to find
@ConfigurationProperties using `context.findAnnotationOnBean` rather
than `AnnotationUtils.findAnnotation`. This will correctly find the
annotation even if the bean is an interface based proxy.

Fixes gh-1927
Merge branch '1.1.x'