Initialize hit count for new lines to total number of accesses so far.
Add flag for dumping out cache stats to file.

Use -bf-dump-cache flag in conjunctin with -bf-cache-model to dump a log
of all cache information (hits associated with each line) to the file
"cache.dump" in the working directory of the running application.
One one access happens per line, not per byte.

Before, each byte address requested would count as a separate request.
This has been replaced with a count of the number of cache lines
touched. It's possible that all addresses fit entirely inside a single
line, and therefore only count as a single access. However, it's
possible that the request is not aligned, and would then require
multiple cache requests.
Remove -bf-unique-bytes as a prereq for -bf-cache-model.

Recording -bf-unique-bytes is no longer a prereq for the cache model,
although the two can work together.
Increment total accesses with the number of distinct cache lines requested.
Tally unique hits to the cache and sum total hits later.

During execution, only record unique cache hits, associating a hit
with the cache line. At the end of execution, the total number of
hits a cache size N would have is equal to the sum of all unique
hits to caches sized N and smaller.