update luajit to 2.0.1-hotfix 1

closes #73
add node.js

closes #71
bump kernel to 3.8.5
dropbear: update to 2013.56
butch: bump to 0.2.1 (supports new update switch)
add rsync
binutils: add patch for sort-section bug
busybox: remove workaround for ld sort-section bug
add rsync to pkg
write-hd-image: check if rootfs is unmounted
add convenience script for building dual kernel
nodejs: fix build errors on i386

closes #71
add libtorrent
add rtorrent
mksh: bump to r44
kernel: bump to 3.8.6
parallelise mksh build while retaining LTO
restore previous "set -e" state upon exiting build fragment
Merge pull request #75 from mirabilos/master

parallelise mksh build
mksh: fix build error due to gcc46-specific flag