Reorder properties

Move more common properties to the front of property lists,
so that they can be passed as constructor arguments.
E.g.

parser:option "-p" "--port"
   :description "Port number."
   :default "8080"
   :convert(tonumber)

can now be expressed as

parser:option("-p --port", "Port number.", "8080", tonumber)

spec/options_spec.lua

@@ -152,9 +152,7 @@ describe("tests related to options", function()
       describe("Options with optional argument", function()
          it("handles emptiness correctly", function()
             local parser = Parser()
-            parser:option "-p" "--password" {
-               args = "?"
-            }
+            parser:option("-p --password", "Secure password for special security", nil, nil, "?")
             local args = parser:parse({})
             assert.same({}, args)
          end)