Merge pull request #1 from moment/develop

Fetch update
Add Macedonian Language
Merge pull request #1337 from B0k0/develop

Add Macedonian Language
Ignore tests when publishing to npm
Merge pull request #1343 from Frost/develop

Ignore tests when publishing to npm
Merge pull request #2 from moment/develop

Merge commits from upstream
use YYYY-MM-DD for L in lang/zh-cn.js
Merge pull request #1346 from zenozeng/develop

use YYYY-MM-DD for L in lang/zh-cn.js
Fix zerofill for negative numbers
Add YYYYYY format for iso string
Use YYYYYY format in iso string for big and negative years
Fix tests
Merge pull request #1348 from ichernev/bugfix/YYYY-handle-negative

Fix leftZeroFill for negative numbers
Merge pull request #1349 from ichernev/feature/iso-long-year-format

toISOString supports long and negative years