lualoader: Handle comma-separated kernels as well

The format for kernels is documented as being space-delimited, but
forthloader was more lenient on this and so people began to depend on it.

A later pass will be made to document all of the fun features that forthloader
allowed that may not be immediately obvious.

Reported by:	mmacy
Approved by:	re (kib)

stand/lua/core.lua

@@ -185,7 +185,7 @@ function core.kernelList()
 	end
 
 	if v ~= nil then
-		for n in v:gmatch("([^; ]+)[; ]?") do
+		for n in v:gmatch("([^;, ]+)[;, ]?") do
 			if unique[n] == nil then
 				i = i + 1
 				kernels[i] = n