[OE-core] how build but do not install package

[Dvorkin Dmitry]

Dear OE-developers!

I'm building an image and SDK for my device without any problem. But I'd 
like to build some extra packages during the time I'm building my image 
or SDK, but I don't want to install this group of packages. Just keep 
them in /deploy/rpm/ or /deploy/ipk, available for installation by the 
package manager. Also I'd like to automatically rebuild them if some 
dependencies are changed.

How to do it correctly using bitbake/yocto/oe?

How to create group of packages and rebuild them if something is 
changed, but do not install into SDK or image.