bug fix for octave under windows and hybrid unix-windows clusters.

Manual cherry pick from commit:
Commit:84f0d6c7daad7c34fc22a76a541d1004528c3524
allow posterior irf plots for octave

Manual cherry-pick from commit:fe0054f370d7c3552eb275e380b3760836ea21d9
fixed bug with seeds in hybrid matlab-octave parallel clusters

manual cherry-pick from Commit:09bc0a0aaae21c036d51b562d8d280d61905bc6b
1) used Environment input argument to GiveCPUnumber to fix bug with hybrid unix/windows clusters;
2) removed return after failure of ping; some machines like hal can be connected but do not allow ping;
(cherry picked from commit 0fb688136e453c1eb5b6a2125fbb0cc46b5fedfd)
synchronization pause(1) to fix bug in matlab-octave clusters under unix
(cherry picked from commit 8de02041ef49c845bc876a96da2fbc614509d31d)
fixed output argument as a proper char matrix for both unix and windows OS.
(cherry picked from commit 844cbac2b3ecfdc7b047b6a703106e6cdb7da64d)
Several bug fixes:

1) properly manage hybrid matlab/octave computations;
2) check for function handles under octave, which cannot be saved on a mat file;
3) bug fix for non standard octave path;
4) synchronization fix under octave;
5) Retrieve missing output files when remote threads are finished;
6) check if input files have been updated, like in metropolis computations with load_mh_file=1;
7) check if output files are missing to trap synchronization failures: this may be inefficient and needs to be improved for unix/windows clusters;
8) fixed cleanup with multiple remote nodes.
(cherry picked from commit c9402d9ecc1d063a96e583d82a07028aeadc49eb)
Merge pull request #356 from rattoma/4.3

4.3ç cherry picked parallel fixes