Add diagnostics that report credit counts to AGAS; they are enabled at debug level
logging only.
Don't zero out negative credit counts in decrementer.
Add configuration macro for new AGAS diagnostics.
Work on #1010, add new diagnostics to AGAS which dump the refcnting tables to the AGAS
logs. Also, changed all the addressing service logging to go through the AGAS logging
channels instead of the main HPX channel.
Unify behavior of gid_type comparison operators WRT credits.
Fix bad assertion.
Removing obsolete command line option
Resolved merge conflict
Adding hpx::unmanaged.hpp(id)
Minor cosmetic changes