Compute half transmissibilities based on local coordinate system

hTrans(cellFaceIdx) = K(cellNo,j) * sum( C(:,i) .* N(:,j), 2) / sum(C.*C, 2),

Only for diagonal tensors, off-diagonal permeability values are ignored
without warning.

Comments: 
1)  In the future I would think it would be beneficial to add a transmissibility calculation class that's takes care of the transmissibility calculation, the multipliers, etc in opm-core. For now the local transmissibility calculation are added to GeoProps.
2) I have not yet added a option for the user to choose the transmissibility approach. Do we want the user to be able to pick the transmissibility approach? Or should they stick to the Eclipse way. 
3) Some negative transmissibilities are present in the Norne deck. The absolute value is used for these transmissibilities. 

Tests: 
Does not change the results for SPE1, SPE3 and SPE9 as expected. 
Improved match on a variant of the reduced norne case where the wells are adjusted to make the case more dynamic. 
This modification could be relevant also for the other routine. Have you checked if that too produces negative transmissibilities on Norne? Also: why use the absolute value and not zero? Zero seems more reasonable to me.