Remove old TODO

TODO

@@ -15,8 +15,5 @@
 - stderr isn't flushing on exit
 - ReadStream should not use an offset in calls to fs.read
   (so that it can pull in files larger than 2G)
-- fs.readFile and fs.readFileSync need to not stat and prealloc a buffer 
-  based on size but rather read until EOF into a chain of buffers, then 
-  concat them together.
 - process object should be defined in src/node.js not in c++
 - Test for EMFILE accept spin bug.