Fixed a bashism with the use of $RANDOM in hgeditor.
The variable $RANDOM is not POSIX so a portable /bin/sh may not define
it. When creating a directory with a random name it's better to use
mktemp, which, even though is not POSIX, exists in common Unixes
including Linux, OpenBSD, FreeBSD and MacOS X.
adding a
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
a renamed from b:37d9b5d994eab34eda9c16b195ace52c7b129980
% test with --rev
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3