Improved read/write performance

- treat binary-data directly
- read from fd up to 64kB at a time
Merge pull request #156 from ichizok/improve-readwrite

Improve read/write performance
Revert "Improve read/write performance"
Merge pull request #157 from Shougo/revert-156-improve-readwrite

Revert "Improve read/write performance"
Change default timeout