Implement Protocol v7 and Timezone

[hun-a]

This PR related with issue #52.

I changed PROTOCOL_V6 to PROTOCOL_V7 and implemented the Timezone.

Default Date of javascript contains local timezone offset and automatically transform the Date as local timezone when you call the method of toString or etc.
As above reason, Timezone result was not same as CSQL interpreter.
So, I created Timezone.js module for handling CUBRID Timezone types that based moment-timezone API.
Timezone module contains format() method that could print as custom format like TO_CHAR(date_time) of CUBRID.

For example:

const Timezone = require('./Timezone');

const date = new Date(Date.UTC(2017, 3, 5, 16, 30, 30, 300));
const timezone = 'Asia/Seoul KST';

const timezoneData = new Timezone(date, timezone);
console.log(date);
console.log(timezoneData.format('YYYY-MM-DD HH24:MI:SS.FF TZD TZH:TZM'));
console.log(timezoneData.format('DY, DD MON YYYY HH24:MI:SS.FF GMT TZH:TZM'));
console.log(timezoneData.format('YYYY-MM-DD'));
console.log(timezoneData.format('HH24:MI:SS.FF'));

result:

2017-04-05T16:30:30.300Z
2017-04-05 16:30:30.300 KST +09:00
Wed, 05 Apr 2017 16:30:30.300 GMT +09:00
2017-04-05
16:30:30.300

Please check my PR and review. Thank you 😄

[kadishmal]

I will review the code soon. May take some time as the PR seems to be big.