Support PG/EPAS 12

Support PG/EPAS 12.

Earlier commit missed to change the Makefile.meta and .legacy
for the v12 support.  So this commit fix the same as well as
fix few other warning due to v12 API changes.

Support PG/EPAS 12

Commit fixes the issues which caused compilation error when compiled
against PG/EPAS 12.

Fix build issue with v11.

Fix a build issue with v11.

Upstream commit 8237f27b504ff1d1e2da7ae4c81a7f72ea0e0e3e removed
get_relid_attribute_name and added missing_ok get_attname so it
can serve the purpose of get_relid_attribute_name.  This commit
replace get_relid_attribute_name() to get_attname().

v11 support and other small fixes

REL-5_2_2

Add PostgreSQL version 11 to all Makefiles.

Fix a issue in the build process

The "create extension mongo_fdw" was failing due to an issue in the Makefile.meta file. This is now fixed.

Fixed a build issue caused by reapplying a patch already done by community.

This release fixes a build issue which was caused by reapplying json_compilation_error.patch that was already applied by the community. Also updated the extension version.

Support for PG 10 server, parameterised query push-down and other enhancements and bug fixes

This mongodb_fdw release contains the following enhancements

1- Support for PG 10 server.

2- Added support for authentication database in the CREATE SERVER declaration. See commit

15ea688

3- Added support for push down of parameterised where clause. See commit

265f72f

4- Provide support for JSONB as type of special __doc column. See commit

17687ce

5- Add support for replica set in CREATE SERVER declaration. See commit

510388f

6- Added function to get extension version. See commit

84d1638

7- Bug fixes

Includes compatibility changes for PostgreSQL 9.5 & 9.6 , JSON and SSL support in the meta driver and other bug fixes

This is major release for MongoDB FDW, in addition to important bug fixes it also contains the following features -

1. Support for PostgreSQL 9.5 - Issue (#67)
2. Support for PostgreSQL 9.6
3. SSL based authentication support in the meta driver
4. Support for JSON types in the meta driver - Issue (#10)
5. Full document retrieval, this feature allow the user to retrieve full mongo document in a single JSON field. - Issue (#32)

REL-4_0_0

Specify database in connection URI for meta driver.