* Support device group definitions from v2
Disable editing v2 groups.
V2 Device groups are defined as follows:
pattern = WHERE query with ? placeholders for values
params = json encoded array of values
* Can't array_unshift something that isn't an array...
Keeps the look more in line with the navigation bar icons.
In the future with Bootstrap 4, Glyphicons will not be included, so this
starts the transistions away.
