major changes to the Spring Tools 4 for Eclipse distribution

• updated to Eclipse 2021-03 release

reminder

• the Eclipse-based distribution of the Spring Tools 4 requires a JDK11 (or newer) to run on
• ships with an embedded JDK15 runtime, no need to install or configure a specific JDK to run the IDE on anymore

additional changes

• (Spring Boot) enhancement: .sts4 dir location now configurable (#601)
• (Spring Boot) fixed: sometimes live hovers do not disappear (#609)
• (Eclipse) fixed: debugger didn't connect automatically to apps deployed to docker from the boot dashboard
• (Eclipse) fixed: STS 4.8.0 template proposals invalid (#579)
• (Eclipse) fixed: Fresh sts-4.9.0 starts with errors - no way to add Task repository (#606)
• (Eclipse) fixed: Error on installing Mylyn JIRA Connector in STS 4.9.0 (#599)
• (Eclipse) fixed: Duplicate com.sun.xml.bind installed screw other plugins (#588)
• (Eclipse) update: remove WTP-based HTML tooling from Spring Tools 4 distribution (#572)
• (CF Manifest) fixed: Error writing config: rename ~\.cf\temp-config025076595 ~\.cf\config.json: Access is denied. (#577)
• (OpenVSX) fixed: the Spring extensions are back on the OpenVSX marketplace (#583)
• (Concourse) improvement: Add display property to pipeline schema (#607) - contributed by @jghiloni

We skipped further 4.9.x release due to no major updates or bug fixes around at that time, and focused our work on the 4.10.0 release instead.