git-annex find is now RawFilePath end to end, no string conversions.
So is git-annex get when it does not need to get anything.
So this is a major milestone on optimisation.
Benchmarks indicate around 30% speedup in both commands.
Probably many other performance improvements. All or nearly all places
where a file is statted use RawFilePath now.
Only done on those calls to getFileStatus that had a RawFilePath, not a
FilePath. The others would probably be just as fast if converted to use
it with toRawFilePath, but I'm not 100% sure.
Note that genInodeCache' uses fromRawFilePath, but that value only gets
used on Windows, so on unix the thunk will never be evaluated.
Now there's a ByteString used all the way from disk to Key.
The main complication in this conversion was the use of fromInternalGitPath
in several places to munge things on Windows. The things that used that
were changed to parse the ByteString using either path separator.
Also some code that had read from files to a String lazily was changed
to read a minimal strict ByteString.
