Merge branch 'ds/sparse-checkout-harden'

Some rough edges in the sparse-checkout feature, especially around the cone mode, have been cleaned up. * ds/sparse-checkout-harden: sparse-checkout: fix cone mode behavior mismatch sparse-checkout: improve docs around 'set' in cone mode sparse-checkout: escape all glob characters on write sparse-checkout: use C-style quotes in 'list' subcommand sparse-checkout: unquote C-style strings over --stdin sparse-checkout: write escaped patterns in cone mode sparse-checkout: properly match escaped characters sparse-checkout: warn on globs in cone patterns sparse-checkout: detect short patterns sparse-checkout: cone mode does not recognize "**" sparse-checkout: fix documentation typo for core.sparseCheckoutCone clone: fix --sparse option with URLs sparse-checkout: create leading directories t1091: improve here-docs t1091: use check_files to reduce boilerplate