quieting down git-commit (and init-db) in tests

There are more places where the tests have gotten, but I noticed these the most. Some non-portable uses of 'export' have been replaced. I'll try to get to the rest in a day or two, but I'm sleepy and have more things for git-svn to do.

--
 t/t6024-recursive-merge.sh     |   90 +++++++++++++++++++++-------------------
 t/t9200-git-cvsexportcommit.sh |   10 +++--
 t/test-lib.sh                  |    2 +-
 3 files changed, 54 insertions(+), 48 deletions(-)