Adding support for user-initiated actions to executable

For the damage executable, I wanted to be able to send a UserCompanyRequest so as to see what the response was.  Added `highline` to facilitate user input capture.

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Also ended up adding an ICE-specific FIX definition, as the above-mentioned UserCompanyRequest is not part of the the normal FIX spec.  

In addition to adding a definition for the UserCompanyRequest, I also added a UserCompanyResponse message definition, as well as field definitions for all of the ICE-specific fields.  Did **not** get around to decorating the existing message definitions when the ICE field references, however.

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Am adding an issue to refactor the schema definitions; I don't care for the fact that both of the vendor-specific schemas are *mostly* the same as the generic ones, but not quite...  Would prefer to see some import of the generic definition, overriding where appropriate.  Not sure off-hand if (or how) XML would support that...  Icky, either way.  Issue is [here](https://github.com/wearemolecule/damage/issues/4).