Regarding commit 3d200925c9f02d2323e (speedup project model by storing url index)

[David Nolden]

I just wanted to quickly note, that for prettyness reasons, you
shouldn't use "uint" and "IndexedString::fromIndex" etc., but rather
simply "IndexedString". The very idea of IndexedString is that you get
the functionality and type-safety of a string, at the efficiency of an
integer.

The reference-counting of IndexedString is a no-op during normal
operation, so you don't need to worry about its efficiency.

Greetings, David