Added a processContent option
Merge pull request #10 from taka84u9/processContent-option

Added a processContent option
Replace Underscore.js with Lo-Dash
Merge pull request #11 from srigi/c39f2c9c3781e56e01e8a8f42ec899125ca1f28e

Replace Underscore.js with Lo-Dash 
Switching to this.files property per gruntjs/grunt#606.
Add separator option, warn on nonexistent src files and empty output.