quote CMDLINE env var exe name if needed, fix memory leak in expandEnvVars, memory corruption in set command

[boeckmann]

Please review line 218. I am not 100% sure if the +3 in the allocation is correct. This should leave space for two quotation marks and the terminating zero. But previously it was +2 without adding the space for the quotation marks. I do not know where the +2 came from. I think +1 for the terminating zero would have been enough.

Referencing #97

[ecm-pushbx]

Seems correct. I want to do more tests on this, especially wrt separators other than blanks and what MSW 98 SE does for those.

[PerditionC]

I haven't had a chance to test, but once it gets reviewed (assuming nothing comes up), it should be merged.

[PerditionC]

Please review line 218. I am not 100% sure if the +3 in the allocation is correct. This should leave space for two quotation marks and the terminating zero. But previously it was +2 without adding the space for the quotation marks. I do not know where the +2 came from. I think +1 for the terminating zero would have been enough.

Referencing #97

Yes +1 is all that was required, the +2 was probably an error that didn't hurt (well could in a rare situation where memory very very tight have caused an out of memory error) so never corrected.