apps/utils/translate_field: allow mappings to be imported from an external file.
apps/utils/translate_field: allow mappings to be imported from an external
file.

(also moved some of the help documentation into perldocs to allow for
greater verbosity without sacrificing readability.)


git-svn-id: 036a1c5f902f528d79fbac72fb947c91fe594755@128 9f305d85-0c50-0410-b3e0-65f4174694de

johan/crush-tools,johan/crush-tools,johan/crush-tools