Async non blocking connector from Node.js to PostgreSQL via libpq. N-API AsyncWorker class used.

It is my own implementation, based on my own requirements.
1. Fast.
2. Simple.
3. Minimal code size. Aprox 100 lines of c++ code.

Implemented 2 basic calls. PQexec() & PQexecParams() from libpq.
This calls cover over 99% cases and requirements(my own).
A tutorial, describing this project, can be found at the N-API Resource.

Requirements:
1. Installed Nodejs. May be with dev headers.
2. Working node-gyp and npm tools.
3. Working libpq library from PostgreSQL.
4. libpq use login/password/database name environment variables.
5. PostgreSQL's connection string NOT used. No plain text login/pass stored.
6. You _should_ customize ./test/Test.js for meet yours environment.
7. Connector accept ONLY strings. Returns strings. Remember, always pass strings. For example not 5, but '5'

>export PGUSER=username
>export PGHOST=x.x.x.x
>export PGPASSWORD=password
>export PGDATABASE=dbname
>export PGPORT=xxxx

To build and run this program on your system, clone it to your computer and run these two commands inside your clone:

``
npm install
npm test
`
Usage:
How to use, see ./test/Test.js. Connector returns 3 things. ntuples (row count), nfields (fields count). Returned data implemented
as key-value Object properties, key is int. For example, sql_result[0] = '123456'; sql_result[1] = 'test data';` This is loop-optimized.
If blob data returned (picture or other binary data), it encoded/escaped via PostgreSQL server, not connector. Connector simple pass As-Is.