Add observeEvent and eventFilter functions for handling events
Code review feedback, part 1
Add `position` parameter to `navbarPage`
Add inc method to Progress
Re-document with roxygen2 4.0.2
Fix incomplete sentence
Add missing entries to staticdocs index
file upload via <iframe> for IE8
use encodeURI() instead of the deprecated escape()
config.sessionId is in this.shinyapp instead of this
use uploadie instead of upload2 because of  regexec("^/([a-z]+)/([^?]*)" earlier ([a-z]+ won't match upload2)
if evt.target.files is undefined, it is probably IE8; we will use iframe from POST to upload the files later
return a valid response temporarily
the key problem with the form submission was that the name was missing
the iframe does not need src, and we should attach the onload event after it is appended to body, otherwise it will be destroyed immediately
parse the multipart form data POSTed and save the file info in .input
Force IE8 uploads to kick off reactive flush
Add import for mime
install mime for travis ci
IE8 does not support iframe.onload; we need to use .attachEvent() instead