Add direct nonlinear method KU=R for GENERIC elastic (u,F in formulation true equilibrium) problems!!

[luchete80]

v,Uglob[v] 0 1.0 v,Uglob[v] 1 0.0 v,Uglob[v] 2 0.0 v,Uglob[v] 3 1.0 v,Uglob[v] 4 0.5000000000000004 v,Uglob[v] 5 0.2644902430549453 v,Uglob[v] 6 3.845154669895442e-17 v,Uglob[v] 7 2.0 v,Uglob[v] 8 1.0 v,Uglob[v] 9 0.0 v,Uglob[v] 10 0.0 v,Uglob[v] 11 1.0 v,Uglob[v] 12 0.4999999999999998 v,Uglob[v] 13 -0.26449024305494534 v,Uglob[v] 14 -1.4350312591010542e-16 v,Uglob[v] 15 2.0

[luchete80]

But Fyx is not zero, probably because there is not curvature in one element example