Adds support for @ToolUi.Filterable on plain text field.
Adds @ToolUi.Filterable support for number field type.
Adds @ToolUi.Filterable support for date field type.
Changes $.calendar to add .calendarButton-empty for more placeholder-like styling.
Adds support for embedded @ToolUi.Filterable.
Changes ContentSearchAdvanced to show a nicer error message when the predicate isn't valid.