Revert "Fix Tempfile usage under ruby 1.8.7"

This reverts commit b49a6ff4ccd169eef6671263ccb29d3ead957697.
Revert "fsync loose objects before moving into place"

This reverts commit cdf0fdb3e19237a2fe8a2667d774a25b5fa46e76.
Revert "make object writes atomic"

This reverts commit 00a00543a7df025b6503de66b3b5aca4ddaa799b.