Made ets table names clearer by usage

Reuse of ibrowse_lb for named table holding
load balancers and for name of unnamed table
holding connections was confusing.
Aliased remaining production ets table names

For consistency, added macro aliases for remaining
ets table names to be found all in one place.
Updated local rebar to fix problem with eunit

Prior version was "2". New functional tests suite
was not being picked up by local rebar, but was
execute with my local which is version "2.5.2"
which targets the same version of Erlang/OTP
as iBrowse (R16).