Closes #112, #514

Closes #507

The preprocessor implementation of "shocks" is broken, and the ref. manual
entries are empty. Nothing is implemented in MATLAB files. It's better to
remove this for now, until a working implementation is done.

Ref. #136

Added an option for setting the number of points where the posterior kernel is evaluated when using mode_check. Reorganized the options_ global structure wrt mode_check.

Also add stub in the doc for the new options

Ref #389

Closes #414

Closes #320

Closes #351

Closes #307

power of negative numbers

 - new command `log_trend_var'
 - new option `log_deflator' to `var' command

Closes #321

Closes: #276

Closes: #205

Closes: #266

Added the possibility to write graph_format=none, in which case the graphs are displayed (provided nograph and nodisplay options are not used) but not saved.

associated to the endogenous variables in the decision rule.