- add new getPackagesForModule() static method to ImportRewrite and
  change getPackageNamesForModule() to use it
- modify IPackageBinding to add findTypeBinding() method that takes a
  simple name, or a compound name for nested types
- add new code to PackageBinding and RecoveredPackageBinding to
  implement findTypeBinding()
- add new test to ASTConverter9Test

Fixes https://github.com/eclipse-jdt/eclipse.jdt.core/issues/4414