Require Ruby 1.9.2
Replace multi_json with json
Remove fastercsv dependency
Convert to Ruby 1.9 hash syntax
Revert "Fix Ruby 1.8 incompatibility"

This reverts commit 07e1de1303a2db2f64109e48919820d398ca6fad.
Revert "Use File.stat to verify permissions for Ruby 1.8 compatibility"

This reverts commit 48fd52b9a652c079eb03fdd72beb18842da4aabc.