Adding support for the corporation name from the employment history

Adding support for the corporation name from the employment history of t...he CharacterInfo endpoint. This change is on Singularity now and will hit Tranquility on August 26th.

You may not want to actually pull this until the changes are on TQ, but I had a few minutes to spare now so figured I would toss this pull request together. :)

An example of this on Sisi can be found here: http://api.testeveonline.com/eve/CharacterInfo.xml.aspx?characterID=92168909
Not really - dictionary keys are not the same as variables. We already use fields with key `'id'` elsewhere. Yes, we would want to avoid *variables* with nane `id`, but keys are another matter.