folder menu tree add options to limit attributeDef and attributeDefNames

There are existing grouper-ui properties to limit the number of stems (uiV2.treeStemsOnIndexPage:30) and groups (uiV2.treeGroupsOnIndexPage:30) that are displayed in the folder menu tree. The tree also displays attributeDef and attributeDefName items. But there is a hard limit of 10 items, and this is in Java code and not configurable.