Check connection status with a matcher in specs
Test for PQconninfo availability and exclude conninfo and conninfo_hash otherwise.
Update Gemfile
Update travis test environment
Fix travis build
Update postgresql and openssl versions for windows cross build.
Fix cross build for mingw32.
Travis uses the Gemfile, so 'gem install' is obsolete.
Add Connection.conndefaults_hash and add specs for conndefault variants.
'gem install rake-compiler' is still needed for cross build.
Change all remaining Oid <-> VALUE conversions to UINT.
Add missing spec for hash form parameters to #exec_params .
Bundle libpq.dll into gem, because PostgreSQL-9.3 does no longer support static linking.
gcc option -static-libgcc is required for i386-mingw32 build.

Don't use native pg_config for cross build. The paths were overwritten anyways until now.

Remove code that was only needed for static build to libpq.
Merged with 4cc778c5ead7