Merge branch 'jk/test-z-n-unquoted'

t9xxx series has been updated primarily for readability, while
fixing small bugs in it.  A few scripted Porcelains have also been
updated to fix possible bugs around their use of "test -z" and
"test -n".

* jk/test-z-n-unquoted:
  always quote shell arguments to test -z/-n
  t9103: modernize test style
  t9107: switch inverted single/double quotes in test
  t9107: use "return 1" instead of "exit 1"
  t9100,t3419: enclose all test code in single-quotes
  t/lib-git-svn: drop $remote_git_svn and $git_svn_id

diff --cc git-rebase--interactive.sh
Simple merge