Remove debugging
Fix memory/fd leak with pkg repo signing_command
Fix crash when pkg repo rsa-key fails

  INTERNAL ERROR: Function archive_write_close invoked with invalid struct archive structure.
  zsh: abort (core dumped)
Delete temporary txz if pkg repo rsa-key fails
Document pkg-repo signing options and add EXAMPLES
pkg-repo: Return EX_DATAERR if a problem is encountered during packing
pkg repo signing_command: Detect if the command fails and fail early

Also cleanup exit path in cmd_sign() while here.
pkg-add.8: Fix typo

Spotted by:	igor
Revert "pkg repo signing_command: Detect if the command fails and fail early"

This reverts commit d32251745358f37728c8dbc41fbbb4c56d9effbb.

This was not quite ready yet.