Don't react to changes outside of the project

Kit changes etc will last to the very slow reindexing of every thing but normally the all not change the  symbols in the project. And because the source coffee inside of the project will be changed symbols outside of the project are not really interesting. So we should avoid reindexing in that cases. We could provide extra pchs and symbol databases for that kits but this is a very different topic. This could be linked in the pchs and database.