add user munual for parrot_pack env_process create_mountlist
rm parrot/src/README.pack
add parrot_pack env_process create_mountlist into SEE_ALSO_PARROT
Add documentation for parrot packaging facilities.

* ccl/pull/476/head:
  add parrot_pack env_process create_mountlist into SEE_ALSO_PARROT
  rm parrot/src/README.pack
  add user munual for parrot_pack env_process create_mountlist