test-transplant.t: improve test coverage...
test-transplant.t: improve test coverage
* ?, x, q
* not a parent
* --source
* outstanding local changes
* outstanding uncommitted merges
* no revision checked out
* checkopts all+branch+rev
* checkopts all-branch
* checkopts no-args
* checkopts continue+all
* revset:transplanted(...)
* filter corrupted changeset
