quilt: upgrade 0.66 -> 0.67

Changelog:
=========
- Call pager with original LANG environment variable
- Consistently complain early if no series file is found
- Fix handling of symbolic links by several commands
- Tighten the patch format parsing
- Reuse the shell (performance)
- Document the series file format further
- Document that quilt loads /etc/quilt.quiltrc
- configure: Make stat configurable
- series: Minor optimizations
- setup: Don't obey the settings of any englobing .pc
- setup: Default to fast mode
- quilt.el: Fix documentation of quilt-pc-directory
- quilt.el: Load /etc/quilt.quiltrc if ~/.quiltrc doesn't exist
- quilt.el: Fix quilt-editable when QUILT_PATCHES_PREFIX is set

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>