TODO:
  * Fix oh-strip.
  * Make oh-strip obey a missing '-l' option.
  * Check on file ownership and modes.
  * Finish tar archive handling in opkhelper.

Future Plans:
  * Package signing. [1]
  * Calculate "Installed-Size" field values. [2]
  * Compress documentation files. [3]
  * Write an 'opkcreate' script like dh_make to create a new source package.

Notes:
 1: Requires opkg to be built with GnuPG and GPGME.
 2: There is an inconsistency between the Debian Policy and opkg in the units
    of this field.  The Debian Policy defines this field in units of kibibytes:
      The disk space is given as the integer value of the estimated installed
      size in bytes, divided by 1024 and rounded up.
    However, opkg apparently attempts to convert this value from bytes to
    kibibytes in its determination of whether the package's data will fit on the
    system:
      pkg_size_kbs = (pkg->installed_size + 1023)/1024;
    For now, we'll omit this field (as a result, opkg simply won't make sure
    there is enough free space).
 3: Follow the model of debhelper's dh_compress.