Transformation of 2sls or 3sls equations
[xall,lx1,ly1,endoeq,nameinst,lindx1,lindy1]=exploeqs(neqs,lexo,endo,z,namez)
* neqs = # of equations
* lexo = list of independent variables in each equation
* endo = list of dependent variables in each equation
* z = matrix of values of the dependent variables
* namez = matrix of names of the dependent variables
* xall = matrix of the values of the instruments
* lx1 = list of the exogenous variables for each equation
* ly1 = list of the endogenous variables for each equation
* endoeq = list of he names of the endogenous variables for each equation
* nameinst = matrix of the names of the instruments
* lindx1 = list of the indexes of exogenous variables for each equation
* lindy1 = list of the indexes of endogenous variables for each equation