Post data

Allow posting of zipballs instead of built graphs to /routers/{routerId}
I believe we actually want to fail-fast here, because if we don't create the directories there will be later failures due to file paths containing non-existing directories. e.g. we skip the directory entry 'subdir', then we hit a file called 'subdir/file1.txt' and its directory doesn't exist. Probably best to just throw an unsupported operation exception right away.