Reactivate squashfs blocksizes > 64kb for kernel 2.6.28/2.6.32
 - use working lzma callback implementation from kernel 2.6.19.2
 
Caution: squashfs access seams reasonably slower with great blocksizes, especially 1MB (+30s for me)

refs #784

git-svn-id: file:///var/svn/freetz/trunk@10440 149334a1-2f27-0410-a3b9-fc62619ac1e6