Double large kmalloc warning size to 4 pages. It was 2 pages, and ideally

Double large kmalloc warning size to 4 pages.  It was 2 pages, and ideally
it should be dropped to one page but in the short term we should be able
to easily live with 4 page allocations.

Fix the nvlist bug, it turns out the user space side of things were
packing the nvlists correctly as little endian, and the kernel space
side of things due to a missing #define were unpacking them as big endian.

git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@62 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c