stash/reset/checkout -p: optionally use the add --patch backend written in pure C#174

dscho wants to merge 7 commits into

gitgitgadget:js/add-p-in-cgitgitgadget/git:js/add-p-in-cfrom

dscho:other-command-p-in-cdscho/git:other-command-p-in-cCopy head branch name to clipboard