[PATCH v2 0/4] Add more tests of cvsimport

Thanks for all the feedback.  I think I have incorporated it all:

- Renamed the library from t/t96xx/cvs-lib.sh to t/lib-cvs.sh.

- Added t/t9601/cvsroot/.gitattributes to avoid whitespace warnings.

- Fixed the "cvs co" command for when checking out a branch/tag.

- Implemented a recursive diff in test_cmp_branch_tree rather than
  relying on GNU diff features.  It is only a dozen lines of code, but
  please review this carefully as I'm not such a shell jockey.

  I tried using "git diff" but it didn't seem to work for this
  purpose, even if I deleted the CVS directories manually to avoid the
  need for "-x" functionality:

  - If I used --no-index, it insisted on showing differences within
    the .git directory.

  - It didn't seem to find any differences (even when there were some)
    when I didn't use --no-index.

  - I couldn't see any documentation that the return value is nonzero
    iff differences are found.  In my tests the return value was
    always zero.

  The library can always be changed later to use "git diff", but I
  don't see this as urgent.  It would also have the disadvantage of
  making "git cvsimport" tests fail if there are bugs in "git diff".

I also added another test script, t9602, in the (new) 5th patch in the series. It tests "git cvsimport"'s handling of branches and tags. Only 5/11 of the tests in this script pass.

Cheers, Michael