backdrop api: rework every single frame sizing

This commit breaks alot of compatibility and maybe
other things too. The change was necessary, because
the old framework ran up against its limits.
A lot of new configuration options are now possible
and some of them were already added.

env/functions.lua

@@ -1,4 +1,4 @@
--- a real "round" instead of ceil or floor 
+-- a real "round" instead of ceil or floor
 function round(input, places)
   if not places then places = 0 end
   if type(input) == "number" and type(places) == "number" then
@@ -7,3 +7,18 @@ function round(input, places)
     return floor(input * pow + 0.5) / pow
   end
 end
+
+function strsplit(delimiter, subject)
+	local ret = {}
+  local sector = subject
+  while true do
+    local pos = strfind(sector, delimiter)
+    if pos then
+      table.insert(ret, strsub(sector,1,pos-1))
+      sector = strsub(sector,pos+1)
+    else
+      table.insert(ret, sector)
+      return unpack(ret)
+    end
+  end
+end