r=phil

land b_cray_portals_merge on HEAD.  This consists of four families of changes:

1) Eric's work to change some APIs in Lustre's portals to come into line with
   Cray's portals and the spec.

2) add --with-cray-portals= to the build and use it to cut up the build
   when we're building lustre against external includes for Cray's portals.

3) Move some facilities from portals.o into libcfs.o so that Lustre can
   consume them when it is running against Cray's portals.o.

4) Fix up the liblustre build.  These changes have also made it to
   b_cray_delivery recently.