development version unit viewer

[DreadKnight]

The game page could display the development version when on localhost to make things a bit easier and less confusing or show a link to the development version.

The unit page/viewer could use some link variable and a div with a notification and a button to easily toggle that on/off when on localhost. When turned out, the data.json file used will be the one from development/deploy/units/data.json
This will allow me to check out and edit the data easier without always having to update the units/data.json file or constantly syncing the two different versions.