[Ohrrpgce] SVN: teeemcee/13092 spawn_and_wait now captures exitcode and stderr on Unix (including Mac)

[subversion at HamsterRepublic.com]

teeemcee
2022-09-02 20:05:46 -0700 (Fri, 02 Sep 2022)
383
spawn_and_wait now captures exitcode and stderr on Unix (including Mac)

Previously it did zero error checking except on Windows (and gfx_console)

But grabbing stderr is off by default. And I don't think it'd ever be supported
on Windows.

Also I fixed the paths in the app_wrap/dummyscript to use absolute paths
rather than relative (a potential problem I mentioned in issue #1145)
---
U   wip/common.bi
U   wip/common.rbas
U   wip/util.bas