Get file value from request and decode

file value now can be received from POST or GET (REQUEST), as we will be
passing in POST via XHR in future
html_entity_decode the value so we can have special chars
Request, decode

REQUEST used as param may be over GET or POST (under XHR setup now) and
html_entity_decode it
fileURLPart is now fileURL and POST'd in XHR send, not part of URL to
get
file now POST'd and can be sent to serverqueue