Input streaming support

[jorgebay]

(Split from #18)
Using the prepared statements, as queries are binary, it would be possible to use streams as input parameters for blobs.

Use cases

• Store streams coming from network or large files.

Sample

var fs = require('fs');
//a file stream, it could be any readable stream
var fileStream = fs.createReadStream(filePath);
var query = 'INSERT INTO table1 (id, big_blob) VALUES (?, ?)';
//pass the stream as an argument
client.executeAsPrepared(query, [1, fileStream], function (err) {
  //...
});