a first rough implementation for testing 'bonding' myplc's

typicallly, you would have 2 complete builds b1 and b2

then on testmaster in b1 you can do
$ run --bonding b2
or simply
$ run -g b2

in order to expose the nodeflavour and slicefamily provided by b2 to build b1

for now it only does the partial-rpms & yum install bootcd nodeimage noderepo & packages reindexing

need some more work to bring a actual nodes and slices online