scripts/chwd: Prevent removal of base mesa packages (#82)

* scripts/chwd: Simplify split function

* scripts/chwd: Prevent removal of base mesa packages

scripts/chwd

@@ -44,10 +44,9 @@ local function check_on_multilib()
     end
 end
 
--- https://stackoverflow.com/questions/1426954/split-string-in-lua
-local function split(str, sep)
+local function split(str)
     local t = {}
-    for found in str:gmatch("([^".. sep .."]+)") do
+    for found in str:gmatch("([^%s]+)") do
         t[#t+1] = found
     end
     return t
@@ -89,11 +88,11 @@ local function install(packages)
 end
 
 local function remove(packages)
-    packages = split(packages, " ")
+    packages = split(packages)
 
     local pkgs = ""
     for _, pkg in ipairs(packages) do
-        if is_installed(pkg) then
+        if is_installed(pkg) and (pkg ~= "mesa" or pkg ~= "lib32-mesa") then
             pkgs = pkgs .. " " .. pkg
         end
     end