Add comments for the benefit of the lcov tool, marking
lines that cannot be hit. Typically these are fall-back
protection arms that are already covered by earlier checks,
and so it's not worth taking out the unhittable code (in case
someone changes the code between the two places in future).
Make sure that the symbols are always exported and present in c-ares.
Make the headers prefixed with 'ares'.
Removed the inet_ntop.h version as it no longer features any content.
Add 3 new functions to set the local binding for the out-going
socket connection, and add ares_set_servers_csv() to set a
list of servers at once as a comma-separated string.
Signed-off-by: Ben Greear <greearb@candelatech.com>