Merge branch 'jx/clean-interactive'
Add "interactive" mode to "git clean".
The early part to refactor relative path related helper functions
looked sensible.
* jx/clean-interactive:
test: run testcases with POSIX absolute paths on Windows
test: add t7301 for git-clean--interactive
git-clean: add documentation for interactive git-clean
git-clean: add ask each interactive action
git-clean: add select by numbers interactive action
git-clean: add filter by pattern interactive action
git-clean: use a git-add-interactive compatible UI
git-clean: add colors to interactive git-clean
git-clean: show items of del_list in columns
git-clean: add support for -i/--interactive
git-clean: refactor git-clean into two phases
write_name{_quoted_relative,}(): remove redundant parameters
quote_path_relative(): remove redundant parameter
quote.c: substitute path_relative with relative_path
path.c: refactor relative_path(), not only strip prefix
test: add test cases for relative_path