Gruntfile.js: Add JSLint configuration

See #165.
core.js: Make minimal changes to conform to the JSLint standard

See #165.
add settings navigation and code refactoring
Merge pull request #167 from Soundnode/settings-navigation

add settings navigation close #159 and code refactoring
update gitignore
Replace JSLint with JSHint (and .jslintrc); add JSHint to watch task
Merge pull request #166 from jonkri/develop

JSLint checks and core.js conformance
Merge pull request #169 from Soundnode/develop

Merging latest