handle linking to Javadoc for Java standard library

[SethTisue]

would be cool. as per e.g. http://stackoverflow.com/questions/16934488/how-to-link-classes-from-jdk-into-scaladoc-generated-doc

[Atry]

I thought it's a bug in Scaladoc tools per se:
scala/bug#9842
scala/bug#9967

It affects not only JavaDoc URLs but also Scaladoc 2.12 URLs

[ashawley]

Yes, links created by Scaladoc need to be fixed. When the scheme for links is fixed, it will match the JDK link scheme. That is a good thing. However, this is a feature request to support Java standard library linking in sbt's apiMappings, not a bug report.

[Atry]

Sure, the api-mapping for JDK should be added then

[Atry]

Done.

See https://github.com/ThoughtWorksInc/sbt-api-mappings/blob/HEAD/src/main/scala/com/thoughtworks/sbtApiMappings/BootstrapApiMappings.scala