extract random number generators into Control/RngComps (src+tests)


git-svn-id: svn+ssh://svn.cern.ch/reps/atlasoff/Control/AthenaServices/trunk@535404 4525493e-7705-40b1-a816-d608a930855b
dont fail if RngComps failed to compile (or isnt there)


git-svn-id: svn+ssh://svn.cern.ch/reps/atlasoff/Control/AthenaServices/trunk@535432 4525493e-7705-40b1-a816-d608a930855b