Update Makefile to change image for rootbuilder

This will no longer require people build your rootbuilder ( https://github.com/progrium/rootbuilder ) in their host before using this busybox rootfs maker :)
Change Dockerimage to progrium/rootbuilder

same as https://github.com/paimpozhil/busybox/commit/df7497ce652517606b67b38cbc53c282353808bb
Merge pull request #3 from paimpozhil/master

Update Makefile to change image for rootbuilder
add base repo
update location for libs
Merge pull request #6 from pandrew/master

Update repos for trunk
Update path to packages repo

Update the correct path to packages uri and rename it from snapshots to packages.
Add Barrier Breaker repo to include missing pkgs