Merge trunk into HDFS-1073.

Resolved several conflicts due to merge of HDFS-2149 and HDFS-2212.
Changes during resolution were:
- move the writing of the transaction ID out of EditLogOutputStream to
  FSEditLogOp.Writer to match trunk's organization
- remove JSPOOL related FsEditLogOp subclasses, add LogSegmentOp subclasses
- modify TestEditLogJournalFailures to not keep trying to use streams after
  the simulated halt, since newer stricter assertions caused these writes to

git-svn-id: 13f79535-47bb-0310-9956-ffa450edef68
129 files changed
tree: 6ad6bb7fe912179b1d93c928e783ef9389364b7b
  1. common/
  2. hdfs/
  3. mapreduce/