Merge branch 'rk/commit-tree-make-F-verbatim' into maint

Unlike "git commit-tree < file", "git commit-tree -F file" did not pass the contents of the file verbatim and instead completed an incomplete line at the end, if exists. The latter has been updated to match the behaviour of the former. * rk/commit-tree-make-F-verbatim: commit-tree: do not complete line in -F input