bug fix for octave under windows and hybrid unix-windows clusters
allow posterior irf plots for octave
fixed bug with seeds in hybrid matlab-octave parallel clusters
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;
synchronization pause(1) to fix bug in matlab-octave clusters under unix
fixed output argument as a proper char matrix for both unix and windows OS.
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.
Merge pull request #354 from rattoma/master

several bug fixes for cluster computations