re-introduce distill_checkpoint_ready

In the OPAL_ENABLE_FT_CR code path there used to be a variable
'mca_base_component_distill_checkpoint_ready' which got removed.
The FT code was not compiling and while trying to get it to compile
again the old variable was #ifdef'd out. This re-introduces the
variable with a new name 'opal_base_distill_checkpoint_ready'
and enables the code previously #ifdef'd out.

This removes the last hack introduced to get the FT code to compile
again.
bcol/basesmuma: use framework output for error message and fix a rounding error.

cmr=v1.7.5:reviewer=pasha
osc/rdma: fix typo in rdma osc component.

cmr=v1.7.5:reviewer=jsquyres
Add missing headers to tarball