Added tag v0.17.1 for changeset 78846e47d87b
Fix typo in documentation.
Convert specs to expect syntax for RSpec 3

--HG--
rename : spec/lib/helpers.rb => spec/helpers.rb
Merge with 6c2444dc63e1
Fix the path to spec helpers in the manifest
Fix some type mismatches for Oid return values.

Thanks to Mina Naguib for the fix.
Implement PG::Connection#conninfo and use it to test #188
Test for PQconninfo availability and exclude conninfo and conninfo_hash otherwise.