Clean up expired entries, fix whitespace.

Umbraco.gitignore

 # Note: VisualStudio gitignore rules may also be relevant
 
-# =========================
 # Umbraco
-# =========================
 # Ignore unimportant folders generated by Umbraco
-**/App_Data/ClientDependency/
-**/App_Data/ExamineIndexes/
 **/App_Data/Logs/
 **/App_Data/[Pp]review/
 **/App_Data/TEMP/
 **/App_Data/NuGetBackup/
-**/App_Data/FeedCache/
-**/App_Data/courier/revisions/
-**/App_Data/courier/cache/
-**/App_Data/umbraco.licensing.log.txt
-**/App_Data/*.udt
-**/aspnet_client/
 
 # Ignore Umbraco content cache file
 **/App_Data/umbraco.config
@@ -25,8 +15,5 @@
 !**/App_Data/[Pp]ackages/
 !**/[Uu]mbraco/[Dd]eveloper/[Pp]ackages
 
-# =========================
 # ImageProcessor DiskCache 
-# =========================
 **/App_Data/cache/
-Cached/