Added jshint grunt-task
Fixed some troubles reported by jshint
Jshint settings extracted to .jshintrc file
Removed .jshintrc file. Created two subtasks for jshint task: develop and default (for build custom task)
Added default grunt-task to Gruntfile.js
Add watch task to Gruntfule.js
Added some parameters to jshint:build subtask and jshint:develop subtask