add jshint dep, add lint npm script and use it in tests, port jshint configs from assetgraph
lib/AssetGraph.js: fix jslint errors and replace tabs with spaces
lib/i18nTools.js: fix jslint errors
lib/mkpathSync.js: fix jslint errors
lib/resolvers/findParentDirectory.js: fix jslint errors
lib/resolvers/senchaJsBuilder.js: fix jslint errors
lib/transforms/addDataVersionAttributeToHtmlElement.js: fix jslint errors
lib/transforms/buildDevelopment.js: fix jslint errors
lib/transforms/buildProduction.js: fix jslint errors
lib/transforms/checkLanguageKeys.js: remove unused function jshint error
lib/transforms/cloneForEachLocale.js: remove unused dependency and variable jshint error.
lib/transforms/injectBootstrapper.js: fix jshint errors
lib/transforms/logEvents.js: fix jshint errors
lib/transforms/omitFunctionCall.js: remove unused dependency. jshint error
lib/transforms/processImages.js: fix jshint errors.
lib/transforms/registerLabelsAsCustomProtocols.js: fix jshint errors
lib/transforms/runJavaScriptConditionalBlocks.js: fix jshint errors
lib/i18nTools.js: remove stray jshint comment
lib/resolvers/findParentDirectory.js: add missing variable to exception
Merge branch 'feature/jshint'