Partial revert "mon: osd pool set syntax relaxed, modify unit tests"

This reverts commit 08327fed8213a5d24cd642e12b38a171b98924cb, except
for the hashpspool bit.  We switched back to an integer argument in
commit 337195f04653eed8e8f153a5b074f3bd48408998.

Signed-off-by: Sage Weil <sage@inktank.com>