Null check in PivotGridFieldBuilder.cs

http://www.expandframework.com/forum/13-suggestions/3672-null-check-in-pivotgridfieldbuilder-cs.html#5075
context menu for the master-detail does not work as expected

http://www.expandframework.com/forum/6-bugs/3675-masterdetail-win-issue.html#5101
JobScheduler does not start

http://www.expandframework.com/forum/8-discussion/3674-xpand-quartz-jobscheduler.html#5096
13.1.8.5