Make the binaries cleaner in the Makefile.
Add broadcast/wait-style condition varialbles.
Change client function prototypes for ease of use.

Prototypes used to be of the form (const char* obj, size_t obj_sz, ...).
This is inconvenient.  Instead, just treat "obj" as a c-string.
Use the busybee_* utils rather than busybee_mta::* utils
Make replicant signal-safe
Push the "shutdown" command onto the inter-thread queue
Make "make distcheck" pass