add support for host and service groups

[elho]

This adds support to show host and service groups to the geomap module, similar to what the dynmap module supports.

[LarsMichelsen]

Did I get it right that one geomap can only have one type of object? Wouldn't it be better to introduce a object type attribute to, for example, the csv file and then make the geomap able to deal with different kind of objects on a single map?

Btw.: Did you have a look at the new worldmap? It is a lot more flexible than the geomap.

[elho]

Yes, you got that right. Without this change, a geomap can only ever show host objects, nothing else. With this change, it can alternatively show hostgroups or servicegroups as well, but just like the dynmap, only one type at the same time.
I agree that this is a limitation of both. Personally I think this limitation in practice is worse for the dynmap, because given that the location plays a major role for the geomap. Using hostgroups or servicegroups to group systems/services that are at the same location seems like a straight orward use case. The specific use case for our customer (on 1.8.5) are logical components in the field across a whole country, which each consist of multiple hosts, each such component being summarized in a servicegroup.