* Removed distinction between alpha and release targets in Makefile.in.
* added release.stamp target, which tags cvs tree, and updates
"RELEASE-DATE"
* added releasediff target, which diffs tree with source as of
date in "RELEASE-DATE"
* Ticked up version to 3.5.2 (alpha 01 -- but I think we'll moving
away from alpha/non-alpha distinctions).
* updated html to reflect release