ported apps lscor, mv, and rm

there's partially rtest too, if you count that

halyde/apps/rm.lua

@@ -1,4 +1,5 @@
 local file = ...
+local shell = require("shell")
 local fs = require("filesystem")
 
 if not file then
@@ -6,7 +7,7 @@ if not file then
   return
 end
 if file:sub(1, 1) ~= "/" then
-  file = fs.concat(shell.workingDirectory, file)
+  file = fs.concat(shell.getWorkingDirectory(), file)
 end
 if not fs.exists(file) then
   print("\27[91mFile does not exist.")