8178043: Support grouping modules in unified javadoc
Reviewed-by: jjg, ksrini

8160697: HTMLWriter needs perf cleanup
Reviewed-by: ksrini, bpatel

8035473: [javadoc] Revamp the existing Doclet APIs
8146529: Update the new Doclet API
8146427: "-nohelp" option issue
8146475: "-helpfile" option issue
Reviewed-by: alanb, bpatel, ihse, jjg, jlahoda, mchung, ogb, vromero