That actually were two bugreports:
* crash after 2x "Force Dump": fix by not doing reload
* reload resulted in crash: fix by resetting FunctionListModel
  when switching to new data model. FunctionListModel still
  had a list of then invalid pointers to TraceFunction's.

The last point actually solved another issue: previously,
old selected function (from config) were not restored after
loading, because the the FunctionListModel was not yet populated
with existing TraceFunction's.

svn path=/trunk/KDE/kdesdk/kcachegrind/; revision=1227334