Previously, if the command given to Valgrind didn't exist, the 'stat -c'
suid/sgid test failed, and the startup script aborted with an ugly message.
I've changed it so that it first checks that the program exists in the user's
path (as determined by 'which'), and aborts if not.

This was quite fiddly to get right;  yell if I've broken anything.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@1967 a5019735-40e9-0310-863c-91ae7b9d1cf9
1 file changed