Use sync(1) instead of sleep(1)

 - the invocations of sleep(1) seem to be to wait until changes are
   actually written from cache to disk. But depending on the underlying
system they might even never be committed or take longer than the
specified sleep(1) amount. If you want to wait until the cache contents are
committed, use sync(1) instead.
Use fallocate instead of dd-ing zeroes if available

 - there is no need to stress the harddrive/SSD and wait until half a
   gigabyte of zeroes are written to a file
 - since linux is assumed anyways, the linux specific fallocate call can
   be used to allocate large files filled with zeroes in a few milliseconds
   and without the need to write the zeroes manually
change kernel build scripts to use defconfig
fix building modules
build kernel outside of kernel tree
Update README.md

Fix markdown format problems on github and better explanation.
make kernel-build uses setup-env and allow for local configuration
fix typos in readme
add install directory
add script for building boot.scr
get rid of bash-specific source command
fix issues on clean build

codesourcery url had 302 redirect so changed it.
libc6-i386 required by codesourcery is not installed by default debian build.
system requirements and more detailed instructions
fix section link
fix typo and more clarifications
make defconfig much more versitile at managing the kernel configuration
Merge branch 'master' of github.com:mindboards/ev3dev-rootfs into defconfig

Conflicts:
	ev3dev.config
add instructions for creating a debian package
Merge remote-tracking branch 'josch/syncnotsleep' into defconfig
Merge remote-tracking branch 'josch/usefallocate' into defconfig