[Rd] Windows Source Install Without Rtools

[Gabor Grothendieck]

Regarding this from this week:

2.10.0 PACKAGE INSTALLATION (Windows)
It is possible to install source packages without Rtools provided they
have no compiled code and no configure.win or cleanup.win script.

- what are the instructions to perform such a source install?
- I assume one still needs MiKTeX -- is that right?
- is the source install done from a tar.gz (in which case one would
need tar to create it) or directly from the source directory tree?