Improperly handles placement and formatting on input-group with existing input-group-addon

[robross0606]

When attempting to add spinner features to an input-group that has an input-group-addon, on off multiple bad things happen depending upon the passed in settings. If verticalbuttons are set, input-group with an existing add-on get regular horizontal buttons. Regular horizontal button CSS also incorrectly rounds the wrong corners and doesn't properly adjust the margins.