Add the [int] setting type for settings that are a list of integers.

The RegExpValidator (more of a restrictor than a validator) requires the
text to start with a '[' and then have a sequence of integers separated by
commas. A trailing ']' is accepted.

cura/CuraApplication.py

@@ -107,6 +107,8 @@ class CuraApplication(QtApplication):
 
         SettingDefinition.addSettingType("extruder", None, str, Validator)
 
+        SettingDefinition.addSettingType("[int]", None, str, None)
+
         SettingFunction.registerOperator("extruderValues", cura.Settings.ExtruderManager.getExtruderValues)
         SettingFunction.registerOperator("extruderValue", cura.Settings.ExtruderManager.getExtruderValue)
         SettingFunction.registerOperator("resolveOrValue", cura.Settings.ExtruderManager.getResolveOrValue)

plugins/PerObjectSettingsTool/PerObjectSettingsPanel.qml

@@ -209,6 +209,8 @@ Item {
                                 {
                                     case "int":
                                         return settingTextField
+                                    case "[int]":
+                                        return settingTextField
                                     case "float":
                                         return settingTextField
                                     case "enum":

resources/qml/Settings/SettingTextField.qml

@@ -98,9 +98,9 @@ SettingItem
 
             selectByMouse: true;
 
-            maximumLength: (definition.type == "str") ? 20 : 10;
+            maximumLength: (definition.type == "[int]") ? 20 : 10;
 
-            validator: RegExpValidator { regExp: (definition.type == "str") ? /^.{0,20}$/ : (definition.type == "int") ? /^-?[0-9]{0,10}$/ : /^-?[0-9]{0,9}[.,]?[0-9]{0,10}$/ } // definition.type property from parent loader used to disallow fractional number entry
+            validator: RegExpValidator { regExp: (definition.type == "[int]") ? /^\[(\s*-?[0-9]+\s*,)*(\s*-?[0-9]+)\s*\]$/ : (definition.type == "int") ? /^-?[0-9]{0,10}$/ : /^-?[0-9]{0,9}[.,]?[0-9]{0,10}$/ } // definition.type property from parent loader used to disallow fractional number entry
 
             Binding
             {

resources/qml/Settings/SettingView.qml

@@ -217,6 +217,8 @@ Item
                     {
                         case "int":
                             return "SettingTextField.qml"
+                        case "[int]":
+                            return "SettingTextField.qml"
                         case "float":
                             return "SettingTextField.qml"
                         case "enum":