Delta BGs
  - Delta 35% font size, right of BG
  - BG font size reduced from 900% to 800% to fit existing d3.min.js formatting w/o errors
  - Delta formatted as +N, -N, +/-N
  - Retro works w/ strike-through
  - Delta colors do not follow BG trend (per Scott L.'s wip/iob-cob defaults)
    - 0+4 = grey delta
    - 5-9 = yellow delta
    - 10+ = red delta

TODO - Finalize HTML/CSS formatting of BG / Delta
TODO - Determine color behavior; independent of BG trend or follow BG trend?
update css
Update index.html
update client.js

format delta for mmol
add "mmol" and "mg/dL"
formatting; flat delta reverts to wip/iob-cob default; delta color follows bg/trend color
Tweaked font size down a touch so it fits better on mobile devices.
another font tweak
another font tweak
another font tweak
try adding support landscape on smaller screens
more resize hacking
Increase BG font size after Jason's commit.
adjust chart font sizes in the chart, for better landscape display on small screens
Added comments to deltaToColor per Scott's suggestion is PR
Merge branch 'wip/bgDelta' of https://github.com/jimsiff/cgm-remote-monitor into wip/bgDelta
Retro delta always b/w
Revert "Retro delta always b/w"

This reverts commit 26e4bb2b59837b8f715f9c9b1cbe0045d4782e81.
Do not display delta if bg is '---'
Retro delta always b/w
Merge branch 'wip/bgDelta' of https://github.com/jimsiff/cgm-remote-monitor into wip/bgDelta