enhance "tests passed" messages to include test dir
generate empty priv/charset.def for rebar builds
fix broken srcdir tests

Commit a04e38a fixed building the tests with rebar, but broke the
test/t11/srcdir tests when built and run with make. This commit reworks the
approach to allow the tests to run correctly and also build correctly with
rebar.
allow embedded listen IPs to be supplied as either lists or tuples