appsdk-bump-app-catalog 549 bumping sdk to 2088-48476f4

sdk commit: RallySoftware/appsdk@41d2376f77e14ded95bb133628870616558a7b0a
author: Stefan Kendall and Ben Wittenberg
message: DE20882 Fixed fieldbucket and tooltips leaking memory.

sdk commit: RallySoftware/appsdk@48476f479ae9ba93287a6a1d11d53cd4eaa716af
author: Kyle Morse and Alan Brockett
message: S65443: Update help base urls
S65961: update IterationTrackingBoardApp to no longer build models and use the TreeStoreBuilder for building out the grid