Various changes and improvements

[paulplant]

• correctly hide/show sensor countdown when locking the screen with the show clock option enabled
• tidy up of some code in RVC (nothing important)
• comments added to explain arrow type in trend arrow returned by slopeArrow()
• updated units to correctly show mg/dL and mmol/L instead of older-style lowercase "L"
• removal of ":" from the end of the menu row titles where it was present (all localisations)
• storyboard changes to add grey "mins ago" and delta units to make the actual values stand out and match the rest of the home screen UI
• "warming up until xx:xx" added to the Dexcom bluetooth peripheral screen to match the improvement made to Libre 2 Direct screen. Constant value set to 120 minutes.

[m-a-v]

updated units to correctly show mg/dL and mmol/L instead of older-style lowercase "L"

Just a remark. It depends on the country how the L is written. This has nothing to do with oldschool. For example in Germany or Switzerland one would rather write mg/dl (respectively mmol/l).

There are two international standard symbols for the litre: L and l. In the United States the former is preferred because of the risk that (in some fonts) the letter l and the digit 1 may be confused.[8]

[paulplant]

updated units to correctly show mg/dL and mmol/L instead of older-style lowercase "L"

Just a remark. It depends on the country how the L is written. This has nothing to do with oldschool. For example in Germany or Switzerland one would rather write mg/dl (respectively mmol/l).

There are two international standard symbols for the litre: L and l. In the United States the former is preferred because of the risk that (in some fonts) the letter l and the digit 1 may be confused.[8]

Yes, in fact I still use ml when writing, I always have done... but in all regulated/approved apps (Dexcom, Clarity, LibreLink etc) and pretty much all medical papers and studies that I have seen, they always use mL nowadays. This change is just to bring us inline with that.

Either way, it's not even slightly important as we all know what it means and understand perfectly well both forms of writing it :) I'll leave it up to @JohanDegraeve if he thinks it's worth adding.