test-highlight: factor out function that normalizes pygments output

test-highlight: unify normalization rule of pygments output We had two variants for unknown reason, s/mf/mi/g and s/mi/mf/g. This patch unifies them to s/mf/mi/g so that we can introduce a utility function.

tests: remove protected file forcibly for portability Before this patch, test-command-template.t is timed out on Solaris, because "rm" on permission denied file implies prompting "override protection 0 (yes/no)?" and blocks execution of test script.

tests: dump journal file by python script instead of sed for portability Before this patch, test-repair-strip.t fails on Solaris, because of "sed" on it doesn't work as expected if input contains null ('\0') character.