recovers objects names in a system of equations
[lx,listcoef,ncoefeqs,xx,namexos,boundsvarb]=syslist(l,coef,boundsvarb)
* l = a list of k equations
* coef = a (mx1) vector of coefficients names
* boundsvarb = a vector of bounds or []
* lx = the list of all endogenous variables
* listcoef = the list of coefficients
* ncoefeqs = the list pf sizes of coefficients for each equation
* xx = matrix of exogenous varaibles
* namexos = the vector of their names
* boundsvarb = the vector of bounds