-check return value

git-svn-id: https://gnunet.org/svn/gnunet@34697 140774ce-b5e7-0310-ab8b-a85725594a96
-fix use after free (GCCH_destroy frees 'ch', and then ch->t dereferences it --- Bart, please check

git-svn-id: https://gnunet.org/svn/gnunet@34698 140774ce-b5e7-0310-ab8b-a85725594a96
-fix leaks

git-svn-id: https://gnunet.org/svn/gnunet@34699 140774ce-b5e7-0310-ab8b-a85725594a96
-fix leaks, check RV

git-svn-id: https://gnunet.org/svn/gnunet@34700 140774ce-b5e7-0310-ab8b-a85725594a96
-fix leaks, use asprintf

git-svn-id: https://gnunet.org/svn/gnunet@34701 140774ce-b5e7-0310-ab8b-a85725594a96
-fix leak

git-svn-id: https://gnunet.org/svn/gnunet@34702 140774ce-b5e7-0310-ab8b-a85725594a96
-check RV

git-svn-id: https://gnunet.org/svn/gnunet@34703 140774ce-b5e7-0310-ab8b-a85725594a96
-check RV

git-svn-id: https://gnunet.org/svn/gnunet@34704 140774ce-b5e7-0310-ab8b-a85725594a96