Use nullable to update required field option only if server is 10.1+.
Hide required option if field is non-editable.
Merge branch '#31/improve-layer-settings-required-field-option' into develop
Introduce locale-specific boldness style.
Convert tabs to spaces.
Add custom skins to override hardcoded font boldness.
Apply custom StackedFormItemSkin where applicable.
Apply bold text style to applicable components.
Merge branch '#30/remove-font-boldness-for-east-asian-locales' into develop