Make vtt.js node and npm friendly.
Release v0.10.1
Specify files for npm and node in package.json.
Add keywords to the package.json.
Release v0.10.2
Add vttcue.js and vttregion.js to files list in package.json.
Release v0.10.3
Use 'encodeURIComponent' instead of 'escape' as it is deprecated.
Release v0.10.4
Update node section of README.