When executing a child program check if it can be found alongside the absolute path of icewm-session. Also fix the examination of exit status of icewm and the detection of crashes.
When executing a child program check if it can be found alongside the
absolute path of icewm-session. Also fix the examination of exit status
of icewm and the detection of crashes.

dicej/icewm,dicej/icewm,dicej/icewm,dicej/icewm