LM test for GMM
rlm = gmmLM(ugmm,rgmm,R,nr,np)
* ugmm = tlist result for unrestricted estimation
* rgmm = tlist result for restricted estimation
* R = (#parameters x 1) vector indicating if some parameters have been sat to zero (ex: R = [1,0,0,1]) to recover ugmm('beta') dimension from rgmm('beta')
* nr = number of parameter restrictions
* np = 'noprint' if the user does not want to print the results
* rlm = a tlist with:
-rlm('chistat') = test statisitc
-rlm('pvalue') = pvalue of the test
-rlm('df') = number restriction