This is the hopefully final revision of the patch
to add the -var-info-path-expression command.
The code part of the patch was already approved in:

	http://article.gmane.org/gmane.comp.gdb.patches/34902

This revision has these changes:

	1. Documentation for the new command
	2. Tests for the new command.
	3. A fix for a bug discovered while testing.
	4. Some formatting tweaks.

I attach a delta patch with just those changes, for easier
review, as well as complete patch against FSF HEAD.

Eli, do doc changes look fine?
Daniel, is the code patch still OK to commit?

Thanks,
Volodya