Get the "Decode As" dialog working, albeit with a few warts. It differs

Get the "Decode As" dialog working, albeit with a few warts. It differs
from the GTK flavor in two major ways:

- The "Decode As" and "User Specified Decodes" dialog have been unified.
- You can modify the decode as behavior at any time, not just when you
  have a packet selected.

Revert part of 53498 so that we can move items marked

/*** THE FOLLOWING SHOULD NOT BE USED BY ANY DISSECTORS!!! ***/

from epan/decode_as.h to ui/decode_as_utils.h.

Move "save" code from decode_as_dlg.c to decode_as_utils.c as well.

In packet-dcerpc.c don't register a table named "ethertype". We might
want to add checks for duplicate table names.

To do:
- Add support for ranges?
- Either add support for DCERPC or make DCERPC use a regular dissector
  table.
- Fix string selectors (i.e. BER).

svn path=/trunk/; revision=53910