Log Message:
Update to jam-2.5.2.

This switches over from the perforce jam distribution to the jam
distribution from the FreeType project. This is fully backwards compatible
with the perforce distribution.
The FreeType jam distribution ships with a GNU configure script.
Other differences are added support for shared libraries, macro expansion,
more flexible command line processing and a fix to dependency calculation.

This closes PR pkg/37285 and should make devel/jam build on NetBSD 4.0.