Feature/localization

[Ostoic]

The following changes from MassCraxx's pull request are included in this pull request.

Currently localized clients (using any language other than enUS) run into some problems using the AddOn:

* On joining a raid the message will contain the localized Class name, which is bad when playing on an international server

* Saved raids coming from the client contain localized Raid names, the comparision with the provided raid_list fails.

These changes should solve these issues making sure a predefined Class-Spec name is used for the join message and using a translation lib to compare localized raid names. Unfortunately comparing Raid IDs seems not to be possible so I assume this is the best solution.

Please note I also adjusted the join message a bit ("LFG icc25 - 5857gs Discipline Priest") - I hope we will find a solution to adjust it in-game in the future.

However, a slight modification to the join message as discussed here was added in the hopes that in the near future the join message will become configurable.