Remove jquery and use framework specificly for ajax calls or write own ajax calls about doodle3d-api

[peteruithoven]

Slight downside is that it isn't Node.js compatible, but there is a Node.js specific alternative: https://github.com/bitinn/node-fetch
Maybe, in the future we can do some kind of conditional platform check.

[peteruithoven]

In the mean time we've readded jQuery's ajax because fetch was lacking timeout functionality.
A solution could be adding a timeout wrapper:
JakeChampion/fetch#175 (comment)

If we want to make the API universal/isomorphic we could use: isomorphic-fetch. But beside that it might be slightly easier to test (which I'm not sure of) I don't really see the point.

[casperlamboo]

Note that this is not a connection timeout. This is a response timeout. ... even if the timeout happens, the original request won't be aborted.

This means that when a gcode batch times out it's still plausible it is being send to the doodle box. The api will resend the batch and the same batch will be printed twice.