-use separate message types for TRY_CONNECT and TRY_DISCONNECT

git-svn-id: https://gnunet.org/svn/gnunet@34738 140774ce-b5e7-0310-ab8b-a85725594a96
-make static

git-svn-id: https://gnunet.org/svn/gnunet@34739 140774ce-b5e7-0310-ab8b-a85725594a96
-simplify logic

git-svn-id: https://gnunet.org/svn/gnunet@34740 140774ce-b5e7-0310-ab8b-a85725594a96