remove unused conenction option.

add connection option documentation.
add few tests

documentation/readme.md

@@ -57,6 +57,53 @@ var conn2 = mariadb.createConnection({socketPath: '/tmp/mysql.sock'});
 var conn3 = mariadb.createConnection({host: 'mydb.com', port:9999});
 ```
 
+### connection options
+
+
+#### important option 
+
+    * `user`: string. user
+    * `host`: string. IP or DNS of database server. default: 'localhost'
+    * `port`: integer. database server port number. default: 3306
+    * `database`: string. default database when establishing connection.
+    * `password`: string. user password 
+    * `socketPath`: string. Permits connecting to the database via Unix domain socket or named pipe, if the server allows it.
+    * `compress`: boolean. exchanges with database must be gzip. (=> when database is not localhost). default: false
+    * `connectTimeout`: integer. connection timeout in ms. default: 10 000.
+
+Support for big integer: 
+
+Javascript integer use IEEE-754 representation, meaning that integer not in ±9,007,199,254,740,991 range cannot be exactly represented.
+MariaDB/MySQL server have data type that permit bigger integer. 
+ 
+For those integer that are not in [safe](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isSafeInteger) range default implementation will return an integer that may be not the exact representation. 
+2 options permit to have the exact value :          
+
+    * `bigNumberStrings`: if integer is not in "safe" range, the value will be return as a string. 
+    * `supportBigNumbers`: if integer is not in "safe" range, the value will be return as a [Long](https://www.npmjs.com/package/long) object.
+
+#### ssl
+    //TODO describe all solutions
+    
+    * `ssl`: string/object. 
+    
+#### other option 
+    * `charset`: string. define charset exchange with server. default: UTF8MB4_UNICODE_CI
+    * `dateStrings`: boolean.  indicate if date must be retrived as string (not as date). default: false
+    * `debug`: boolean. when active, log all exchange wirh servers. default: false
+    * `foundRows`: boolean. active, update number correspond to update rows. disable indicate real rows changed.  default: true.
+    * `multipleStatements`: boolean. Permit multi-queries like "insert into ab (i) values (1); insert into ab (i) values (2)". this may be **security risk** in case of sql injection. default: false
+    * `namedPlaceholders`: boolean. Permit using named placeholder, default: false
+    * `permitLocalInfile`: boolean. permit using LOAD DATA INFILE command.  
+    this (ie: loading a file from the client) may be a security problem :
+  
+    A "man in the middle" proxy server can change the actual file requested from the server so the client will send a local file to this proxy.
+    if someone can execute a query from the client, he can have access to any file on the client (according to the rights of the user running the client process).
+    default: false
+    * `timezone`: string. force using indicated timezone, not current node.js timezone. possible value are 'Z' (fot UTC), 'local' or '±HH:MM' format    
+    * `nestTables`: boolean/string. resultset are presented by table to avoid results with colliding fields. default: false 
+    * `rowsAsArray`: boolean. default rows are defined as a JSON object. when active row is an array. default false 
+
  
 ## Query
 `connection.query(sql[, values][,callback])`