Added permutations when resolving recurring DoFs

Calculate permutations matching recurring DoFs instead of full
permutation. Illustrative example:

'cpu cores'<8>,
'users'<50,75,100, 150>, 'Probability dropRequests'<0.0>,
'users'<300>, 'Probability dropRequests'<0.1>,
'users'<400>, 'Probability dropRequests'<0.3>,

Generates 6 permutations: <8, (((50|75|100|150),0.0) | (300,0.1) |
(400,0.2))>