Make EntityListFile.writeEntityList public

[AaronGullickson]

This is a very small PR to make the EntityListFile.writeEntityList() method public. This is a possible first step to merging the entity read/write methods across MM/MHQ. I also need it in the more immediate term to fix problems with BotForce in MekHQ which does not properly read in all of the new deployment information for entities. I could add that deployment information to the MHQ reader/writer but it looks like we are trying to move away from that as I note from the comments at the top of MHQXMLUtility.writeEntityToXmlString, which read:

* TODO : This is dumb and we should just use EntityListFile.writeEntityList.
* TODO : Some of this may want to be back-ported into entity itself in MM and then
* TODO : re-factored out of EntityListFile.

I already have a code change in place for MHQ to fix this problem from the MHQ side, but this method needs to be public first.

[HammerGS]

With the Todo's would this be a draft?

[AaronGullickson]

Nope, not a draft. I am not volunteering yet to do the whole refactoring. But this should allow me to fix the problem in BotForce, where botForces can get all the nice deployment goodies.