Remove many mentions of sampleCount with auto and decltype...

... This makes much code agnostic about how other things (functions and
arguments) are typed.

Many of these neeed to become size_t instead of sampleCount.

src/ondemand/ODComputeSummaryTask.cpp

@@ -240,7 +240,7 @@ void ODComputeSummaryTask::OrderBlockFiles
    //Note that this code assumes that the array is sorted in time.
 
    //find the startpoint
-   sampleCount processStartSample = GetDemandSample();
+   auto processStartSample = GetDemandSample();
    for(int i= ((int)unorderedBlocks.size())-1;i>= 0;i--)
    {
       //check to see if the refcount is at least two before we add it to the list.