gruntjs: added node.js support
Update gruntjs.d.ts
fix underscore string module declaration
Merge pull request #2104 from borisyankov/def/gruntjs

gruntjs: added node.js support
Merge pull request #2105 from borisyankov/def/underscorestring

fix underscore string module declaration
Add url
Merge pull request #2107 from pine613/feature/add_url

Add library "url()", Closes #2106