stringImportPaths should be part of the project

[Kelet]

I have some proto files (for protobuf) in my stringImportPaths. It would be nice if I could edit them from Mono-D. Currently, stringImportPaths do not show up in the project. The "manual" workaround is adding your stringImportPaths as sourcePaths or importPaths but this may not be desirable behavior. For example: If you have D files which are compiled at run-time, but don't want them accessible doing compile-time.