Refactor gulpfile (mainly sprite generation and file watcher)
Remove gulp-clean dependency
Merge branch 'master' into rework-gulpfile

Conflicts:
	gulpfile.js
	package.json
Fixed minor globbing issue
Change "spriteGenerator" function name in "generateSprite"
Add hard version dep on older "gulp-sass" v1.1.0 in order to prevent gulp errors when building
Add statement in README that npm install could display warnings
Merge pull request #1 from fza/rework-gulpfile

Refactor Gulpfile
Fix Typo
Merge commit '0818a44d4ff4d66bdda3b08f85f12642400c11d3'

Add README statement on npm install warnings