Merge branch 'ta/fast-import-parse-path-fix'

The way "git fast-import" handles paths described in its input has been tightened up and more clearly documented. * ta/fast-import-parse-path-fix: fast-import: make comments more precise fast-import: forbid escaped NUL in paths fast-import: document C-style escapes for paths fast-import: improve documentation for path quoting fast-import: remove dead strbuf fast-import: allow unquoted empty path for root fast-import: directly use strbufs for paths fast-import: tighten path unquoting