Cleanup: also cleans up host tools and demos.
Update to new qemu: lazy initialization of socket connection for special GPIO.
bug fix: wrong busybox version in download script
Option to entpack 64bit cross compiler (instead of the default 32bit)
cleanup: command 'make' was not valid anymore
Lua build didn't have '-fPIC' option, needed by qemu build.
Added documentation of necessary packages to be installed in order to build.
Toolchain to be unpacked will be guessed (defualt), it also can be speficied explicitly (32, 64 bits).