confirmed-commit fixes, tests

- fixed typo preventing evaluation of confirmed-commit logic in backend_startup
- fixed uninitialized variable warnings
- added details to CHANGELOG.MD
- added capabilities advertisement for confirmed-commit 1.0 and 1.1
- added xml hello message that uses only eom framing, for simplicity in asynch tests
- add stty restore after wait_restconf to fix console corruption in tests
- adjust test_confirmed_commit to drop perms and run as the invoking user.  This will require running user to have permissions on /usr/local/var/example
- added CLI tests

apps/backend/backend_main.c

@@ -888,7 +888,6 @@ main(int    argc,
     switch (startup_mode){
     case SM_INIT: /* Scratch running and start from empty */
         /* Delete any rollback database, if it exists */
-        // TODO: xmldb_delete doesn't actually unlink; need to look at this
         xmldb_delete(h, "rollback");
 	/* [Delete and] create running db */
 	if (xmldb_db_reset(h, "running") < 0)