fixed bug in global router making the routing matrix too sparse

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@7623 b45a01b8-16f6-495d-af2f-9b41ad6348cc
improved anti-flooding stategy in g-router

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@7624 b45a01b8-16f6-495d-af2f-9b41ad6348cc