[Ovmsdev] Add version strings to the boot partitions on the firmware page

[Craig Leres]

On 11/11/2018 6:53 PM, Mark Webb-Johnson wrote:
> Looks cool. Those prefix and postfix were put there for that reason, but we never got round to doing it.
> 
> How is performance? If acceptable, please send a pull request and we’ll get it merged (unless anyone else has any comments / suggestions)?

I'll measure it but I suspect it's on the order of msecs. It has to read
about 80K of flash to find the version string.

Seems like the version finder code should live in main/ovms_version.cpp?

> Could you extend the ‘ota status’ command to show the same?

Currently it shows:

    OVMS# ota status
    Running partition: factory
    Boot partition:    factory
    Firmware:          3.1.011-16-gb8dc60e-dirty/factory/main (build idf
v3.1-dev-1586-g65355d28 Nov 11 2018 16:39:30)
    Server Available:  3.1.011 (no update required)

    Sun Nov 4 01:53:00 UTC 2018 OTA release
    [...]

Maybe add this after the "Boot partition" line?

    Factory image:     3.1.011-16-gb8dc60e-dirty
    OTA_0 image:       3.1.011
    OTA_1 image:       3.1.011-16-gb8dc60e

I'll try for a pull request next weekend.

		Craig