This commit contains the following changes:
- bml: add a function to add a single process. this function is
intended to remove the need to maintain a opal_bitmap_t as it is
irrelevant for a single proc. BTLs will need to be updated to
either 1) ignore the return code from opal_bitmap_set_bit or not
call the function if the reachability bitmap is NULL.
- bml: add an inline accessor function for getting the bml endpoint
for a peer proc. this function will either 1) return the cached bml
endpoint, or 2) create the endpoint and call add_proc will all
available BTL modules.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>