Manual cherry-pick from
Commit:22e0b9cc3d70f67ffe125a5d0a16805c539c83cc

1) fixed bugs when no estimated parameters are declared;
2) fixed bug for the ML base (bayestopt_.pshape==0);
3) make more transparent the error when the model does not solve at prior_mode or  prior_mean;
4) when prior_mean or prior_mode fail, try 50 times with randomly generated samples from the prior before interrupting identification.

This commit fixes issues related to fabiac forum request and subsequent discussion with Johannes.

http://www.dynare.org/phpBB3/viewtopic.php?f=1&t=4402&p=10771&hilit=identification&sid=64c6f9d987a2641e79dd5722137eb483#p10771
1) trap the case where the model does not solve for any parameter values in the MC sample;
2) fixed initialization of alpha2_stab;
(cherry picked from commit d6993cecc4d5afc90614e817156a18b2d254ffab)
Manual cherry pick from
Commit:b0ce2dacd918d83b2b8ad6f2188a14660e802976

1) better trace all cases when the model does not solve, classifying cases according to info output of dynare_resolve;
2) trap the case of memory allocation limit for too large model undergoing to reduced form mapping
Manual cherry pick from
Commit:92e4e73765fa79c5dffd193c56feec7017ff34cd

Trap the cases where the state space matrices are not stored for memory allocation issues
[to be fixed later by breaking the big matrix stored ...]
bug fix in call to priordens;
(cherry picked from commit 597d30d0bfcacecf45a267f4d3a9c0bfa3786793)
Merge pull request #328 from rattoma/4.3

Identification and sensitivity fixes