Document treatment of parameters in steady state files
(cherry picked from commit 323bfaf353b1f511ba9a8c4cf8fe789a8503ce2c)
Strip estimation DLL, not ready for release.
Harmonize plotting of IRFS

In stoch_simul.m IRFs were only printed if they were not flat instead of checking whether the IRF is different from 0. Unit root responses were thus filtered out, e.g. C=0.2 for all t was not displayed.
(cherry picked from commit c9ebe21fafad941aa53dc3da42a23525f2d8b77e)
Merge pull request #552 from rattoma/4.4

Trap bug with one single estimated parameter for identification
new function write_latex_definitions closes #478

(cherry picked from commit f70ebea94c5ee863eb5e34b2d4d8da7deef0fa2b)
write_latex_definitions: use M_ as global
(cherry picked from commit ea888fe6464d073367adf6811adff03b17cecd40)