Release 3.9.9

What's Changed

• Upgrade org.hl7.fhir.core to 6.4.4 and hapi-fhir to 7.6.0
• Remove the devMode configuration parameter, it is now enabled when httpReadOnly is not #315
• Remove the autoInstallMissingIgs configuration parameter, it is now enabled when httpReadOnly is not #315
• Improve the Matchbox server documentation #315
• Respect the 'onlyOneEngine' mode in MappingLanguageInterceptor #316
• Use the proper encoding when returning a transformed resource #318

Full Changelog: v3.9.8...v3.9.9