8149146: [javadoc] eliminate doclet.xml
Reviewed-by: ksrini, bpatel

8164316: Refine the Doclet APIs
Reviewed-by: jjg

8164130: Simplify doclet IOException handling
Reviewed-by: bpatel, ksrini

8159305: Enhance the javadoc tool to support module related options
Reviewed-by: bpatel, jjg

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

8160301: javadoc RootDoclmpl and DocEnv needs to be renamed
Reviewed-by: bpatel, jjg

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