update stack flags from xo_flags
new 'not-first' flag on XOF_*
add xo subdir
add test for not-first
update with not-first flag
new test case
new test case
new test case
new test case
new test case
new test case
new test case
new test case
new test case
new test case
new test case
new test case
new test case
new test case
new test case