Global strategy for temp directories removal management in wares

[Arthoni]

Following the logic of #1026

Extended logic for temp directory management in all simulators and generators: delete by default, common option to keep them

• Option --keep-tmp-dir or -e in command line to keep temp folders
• ? variable containing list of temp directories to be deleted (according to the env variable), so that delete step can be consistently externalized in the parent class. The only thing to do in each ware class is to fill the list with temporary paths of the current ware

[Arthoni]

General behavior stored in branch auto-remove-all-tmp-files (in Arthoni/openfluid fork) for further developments