Make tests work on Solaris:
- replacement for mktemp
- fall back if shell arithmetic doesn't work
- replacement for 'set -x' (which results look different with some shells)
- "FOO=bar; export FOO" instead of "export FOO=bar"
- don't use 'if ! ...'
+ hg clone http://localhost:20059/ copy
requesting all changes
abort: error: Connection refused
+ echo 255
255
+ ls copy
ls: copy: No such file or directory
+ cat
+ set +x
+ hg clone http://localhost:20059/foo copy2
requesting all changes
abort: HTTP Error 404: File not found
+ echo 255
255
+ set +x