OSTC firmware upgrade partially broken

[Jan Mulder]

Since May 19, 2018 Heinrichs-Weikamp introduced something new with 
respect to firmware numbering. On that date a version was released 
called 2.97 SP1. As I found a simple bug related to CNS display 
yesterday, I was looking at the HW website and found out that I never 
had a message from Subsurface about this new version of the firmware.

Some observations:
1) libdivecomputer seems to report the same (integer) version number for 
2.97 and 2.97-SP1. I just upgraded my OSTC3+, and the version stays 609. 
This seems something for Jef, but not sure this breaks anything at the 
Subsurface end
2) A HW download of a .txt is used by Subsurface to detect the latest 
firmware version available. This .txt looks like this:

************
[2.97]
MD5: ec864820ee576841a2805227d7b39a99

- Stable Version - SP1
<the fixes for this version>

[2.97]
MD5: 2f97a168530d2c86a43bbe382dde92ad

- Stable Version -
<the fixes for this version>

etc.
************

And we do a simple check of the first line. And, we do not detect a 2.97 
SP1 version like this. For us (Subsurface) the easiest way out might be 
to ask HW to number these SP releases like 2.97.1 or explicitly define 
the new firmware versioning scheme, and add some parsing for the SP deal 
at our end.

3) And just upgraded my OSTC to 2.97 SP1 using Subsurface (manual 
selection of the proper .hex file) and that works just fine. So its the 
notification to the user that there is a newer firmware version 
available that is broken.

--jan