8177788: migrate collections technotes/guides into java/util/doc-files
Reviewed-by: mchung, bchristi, martin

8181290: Invalid HTML 5 in core-libs docs
Reviewed-by: mchung, lancea

8177789: fix collections framework links to point to java.util package doc
Reviewed-by: bchristi, martin

8080901: Replace package.html files with package-info.java in the java.base module
Reviewed-by: lancea, alanb, vinnie