Merge pull request #1 from jpallen/master

Add in modular loading, changing scale, reloading pdfs and text selection.
Update grunt build file
Move required CSS for TextLayer into separate css file
Merge Logger.js back into PDFListView.js as it's a core compontent. Make it possible to construct a pdfListView without the textLayer
Remove no longer needed Logger.js file from build.js
Remove old textLayerDiv when re-rendering
Allow clicking on external links