Merge branch 'stable-2.14' into stable-2.15
* stable-2.14:
Document that cache cleaning intervals < 1h are not supported
Apply changes to file-based websession cache from HA-plugin
Update cache cleaner to HA-plugin version and add tests
Add additional tests for websession cash from HA-plugin
Refactor test key assignment in cache tests
Use junit to provide a temporary directory for testing
Simplify cache-directory creation
Adapt system time manipulation to method used in HA-plugin
Reformat code with google-java-format 1.7
Fix getIfPresentObjectNonStringTest
Change-Id: I93edd692e06c6713a6f991f002582735179fafea
