Test flags and alternative invocations

[rec]

The tests are reasonable, but skimpy:

• They don't test many of the possible flags
• Sometimes there are many ways to give arguments and we just give one

Automated testing for more of this is need.

[rec]

• git-all --all --catch --dotfiles
• git-combine --preserve-conflicts
• git-copy/git-rename --all --create --force - also, missing source branch
• git-delete --all