The derivatives with respect to endogenous variables of the previous blocks are corrected for a block-decomposed model without bytecode option

SWZ: remove gsl from build system, to be reintstated if gsl remains a requirement in the ms new code

- fixed bug with batch file for octave;
- fixed screen output for octave;
- cosmethics

- Adds a "lead_lag_incidence" matrix in each block for the endogenous variables belonging to previous blocks (other_endo)

When a model is evaluated with bytecode the residual has to be returned in the equations order (not in the variables order)

print_bytecode_static_model and print_bytecode_dynamic_model commands are documented in the reference manual

Testsuite: fix optimal policy test (options_.qz_criterium is no longer automatically assigned a value)

Preprocessor: in steady_state_model block, allow MATLAB functions which return several arguments (closes #37)

- remove the dirty vpath hack
- factorize between the two estimation DLLs
- factorize within SWZ makefile

Compatibility fix for Octave: under Octave, union() called on a column vector and a scalar returns a row vector, hence the need to add the 'rows' option