Log Message:
pkgtools/mktool: update to 0.1.18

v0.1.18
 - Cargo: Bump pkgsrc requirement for DIST_SUBDIR fix.

v0.1.17
 - fetch: Create all parent directories.
 - symlinks: Add integration tests.
 - symlink: Simplify code with a vec.
 - tests: Use CARGO_TARGET_TMPDIR.
 - distinfo: Fix doc reference.

v0.1.16
 - symlinks: Add initial version.