attached patch checks to see if the $PWD/.gdbinit file is world writable and 
if so, warn about this and refuse to load it

idea being that since you can execute just about anything in it, you dont want 
random people inserting this in it

of course, the usefulness of this is marginalized if .gdbinit is owned by a 
diff user and they just make it world readable but not world writable ... but 
i dont think a cwdbuf.st_uid == getuid() would be accepted ?
-mike