Closes gh-5240

Closes gh-5239

Closes gh-5238

Closes gh-5237

Closes gh-5236

Closes gh-5235

* gh-5197:
  Add nifty-spring-boot-starter to list of third-party starters

Closes gh-5197

* gh-5205:
  Fix namespace declarations in Hazelcast xml's and make them consistent

If a JCache provider is started with hazelcast and the default settings,
the underlying `HazelcastInstance` is disposed at the end of the
process, not when the `CacheManager` is closed.

This commit fixes the only test that use such setup.

See also https://github.com/hazelcast/hazelcast/issues/7606

Closes gh-5209

An overhaul of the `RedisCacheManager` is expected in Hopper (to be
consumed by Spring Boot 1.4). One of those changes is to make sure every
key have a decent prefix by default.

This commit enables the use of prefix as it is disabled by default.

Closes gh-5175

This commit enhances the default launch script to allow the default
values for LOG_FOLDER and PID_FOLDER to be set at build time. They
can now be set using the logFolder and pidFolder properties
respectively.

Closes gh-4787

Previously, JarURLConnection would corrupt a URL that contained a
mixture of encoded and unencoded double-byte characters. URLs that
only contained unencoded double-byte characters were not affected as
they are passed through as-is.

This commit updates JarURLConnection.JarEntryName to correctly handle
characters with a value that won't fit in a single signed byte (a
value greater than 127). Such characters are now URL encoded and then
written to the output stream as multiple bytes.

Closes gh-5194

 - Code formatting
 - Javadoc warnings
 - Deprecation warnings

Upgrade to Jetty 9.2.15 and replace use of API that was deprecated
and changed to throw an UnsupportedOperationException in the same
release.

Closes gh-5218

Closes gh-5212

Closes gh-5224

Closes gh-5223

Closes gh-5222

Closes gh-5221

Closes gh-5220

Closes gh-5219

Closes gh-5217

Closes gh-5216

Closes gh-5215

Closes gh-5214

Closes gh-5213