Added chart scroll and 4x performance

[dimecho]

Please test before merge.

[jsphuebner]

Hi Dima,
sorry I only got to look at this now. Will test the client side changes later. On the server side you moved enabling of fast uart to the setup routine. That only works if the STM32 boots faster than the ESP. Not sure. Also after a software update fastuart will not be enabled again.

[dimecho]

OK fair point about ESP vs STM32 boot time competition. Maybe we can have a Sleep-Delay in ESP on startup? The idea was to keep "CMD" loop as simple and clean as possible, even if statements will slow it down. I had it down to about 10ms for 10 results (with complete path HTTP > ESP > STM32 > ESP > HTTP)

[jsphuebner]

How about handing over control to the client side? You have already started by adding the timeout parameter to the /baud resource. So now you could switch the UART between 115k and 920k with a parameter.
The web interface can then switch to fast uart mode in onload(). Also if it doesn't get reply it can try switching back to 115k