+ Added new file for prior sampling (prior_sample.m). 
+ Undo previous change on prior_draw.m (transposition of pdraw).
+ Bug correction in prior_draw.m.
+ Added field in options_: the default number of mc simulations in the
prior distribution.


git-svn-id: https://www.dynare.org/svn/dynare/trunk@2431 ac1d8469-bf42-47a9-8791-bf33cf982152