fix a place where ParserInterface depended on CompilerInterface

(context: we're trying to remove all dependencies of compiler front
end code on compiler back end and/or engine code)
relocate api.JavaLibraryPath to workspace.JavaLibraryPath

because it's only used there, and because extensions aren't expected
to call it directly, either (extensions go through
ExtensionManager.addLibraryPath)
rename JavaLibraryPath -> NativeLibraryPath

communicates better what it's for
remove isApp flag on headless branch

it isn't used by anything in headless
continue gradually converting AbstractWorkspace to Scala

it really needs cleaning up and the more of it that's in Scala, the
easier that will be
reformat