Fix compile error with theoretically supported versions of libcurl < 7.12.3.
Merge branch 'PHP-5.5' into PHP-5.6
Drop PDO support for extremely old libpq versions

configure will now fail if any of the following function is missing:
* PQprepare
* PQexecParams
* PQescapeStringConn
* PQescapeByteaConn
Deprecated PDO::PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT
Added new PDO::PGSQL_ATTR_DISABLE_PREPARES that uses PQexecParams

Faster than prepared statements when queries are run once. Slightly
slower than PDO::ATTR_EMULATE_PREPARES but without the potential
security implications of embedding parameters in the query itself.
Updated NEWS
Merge remote-tracking branch 'origin/PHP-5.6' into str_size_and_int64_56_backport

* origin/PHP-5.6:
  Updated NEWS
  Added new PDO::PGSQL_ATTR_DISABLE_PREPARES that uses PQexecParams
  Deprecated PDO::PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT
  Drop PDO support for extremely old libpq versions
  Fix compile error with theoretically supported versions of libcurl < 7.12.3.

Conflicts:
	ext/pdo_pgsql/pdo_pgsql.c
	ext/pdo_pgsql/pgsql_driver.c