* tests/init.sh (compare_): Don't use 'diff -u' if it inserts a space
in column 1, like 'diff -c' does.
* tests/test-init.sh (test_compare): Don't repeat the test from init.sh
whether 'diff -u' is used. Instead, test whether the output contains
some '@' character.
* tests/test-init.sh: Remove protective subshell.
Suggested by Bernhard Voelker. While a subshell is normally
required to protect against older shells (Solaris, FreeBSD) that
warn about a missing program before performing redirection, the
shell-selection tests performed by init.sh probably exclude any
offending shell.
* tests/test-init.sh: Also exempt @@ lines from the comparison
of diff output, since Solaris 5.10 and GNU diff formats differ.
Reported by Stefano Lattarini.
