major changes to the Spring Tools 4 for Eclipse distribution

• updated to Eclipse 2020-12 release (including support for Java 15)

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) new: show bean startup performance metrics in live hovers and code lenses (details in the user guide)
• (Spring Boot) new: show basic request mapping performance metrics in live hovers and code lensses (details in the user guide)
• (Spring Boot) new: provide content-assist for constructor-arg name in Spring XML config files (#562)
• (Spring Boot) fixed: language-server-internal exception happening when saving a file that has a space or other special characters in its name or path
• (Eclipse) improvement: added support for custom scripts to create docker images when deploying a boot app to docker in the boot dashboard (details in the user guide)
• (Eclipse) fixed: enable live hover action for more docker-related nodes in the boot dashboard
• (Concourse) fixed: navigation in pipeline files with VSCode Concourse CI extension doesn't work everytime (#483)

We skipped the 4.8.2 release due to no major updates or bug fixes around at that time, and focused our work on the 4.9.0 release instead.