Merge upstream changes

Merge changes from upstream PJAX-standalone. Also clean up comments
Update shushjax.js

Cleanup coding style
Update shushjax.js

more coding style cleanup
Update shushjax.js

even more coding style cleanup
Update shushjax.js

final code cleanup
Update shushjax.js

declare variables properly
Update shushjax.js

much more robust fallback for partial file support, fixes #12
Merge pull request #23 from Team-Pr0xy/dev

Fix bugs, clean coding style, and merge upstream changes