TODO:
  * Fix oh-strip.
  * Make oh-strip obey a missing '-l' option.
  * Handle "Architecture" field in oh-gencontrol, opkbuild, and oh-buildopk.
  * Check on file ownership and modes.
  * Finish tar archive handling in opkhelper.
  * Support "Conffiles".
  * Build packages with copyright information and changelogs. [1][2]
  * Generate MD5 checksums of files.

Future Plans:
  * Package signing. [3]
  * Calculate "Installed-Size" field values. [4]

Notes:
 1: Requires change to format spec.
 2: Package documentation (copyright notices and licenses, packaging changelogs,
    etc.) should be installed in /usr/share/doc/<binpkg>.  There should be one
    set of these files for all binary packages built by one source package.
    This may be accomplished by making one package provide the documentation
    files and be depended on by each of the other packages.  Each of the other
    packages would then install a symbolic link from their documentation
    directory to that of the providing package.  The providing package may be
    one on which all other packages naturally depend (e.g. a common library or
    set of data), or it may be a special "common" package that installs nothing
    but packaging documentation files.
 3: Requires opkg to be built with GnuPG and GPGME.
 4: 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).