temp disable delete error and just log in error log.
Merge pull request #34 from lilinghui/beanseye:fix_delete_failed

temp disable delete error and just log in error log.
fix bug: 1. Delete while one backend down, 2.Close fd after using the
new log fd.

details:
1. delete if just one server error, the error will be cleaned.
2. close fd not driven by GC.
3. remove some useless errlog output.
Merge remote-tracking branch 'upstream/master' into fix_delete_failed
Merge pull request #35 from lilinghui/beanseye:fix_delete_failed

fix bugs and remote log.
delete forgotten to remove importing.
Merge remote-tracking branch 'upstream/master' into fix_delete_failed
Merge pull request #36 from lilinghui/beanseye:fix_delete_failed

fixing
add list fd
make delete always print failed host in any case.
Merge remote-tracking branch 'upstream/master' into fix_delete_failed
Merge pull request #37 from lilinghui/beanseye:fix_delete_failed

modify the log output.
Merge branch 'master' of http://code.dapps.douban.com/beanseye
re-implementation the scheduler and client.

1. the main node will never be swap to [3:] rango of the bucket.
2. Get will just get from main nodes, and ignore the backup nodes.
3. Set will do the same behaviour as before, but the sequence of Set
will set to main nodes first, and then the backups.
Merge pull request #38 from lilinghui/beanseye:optimize_scheduler

re-implementation the scheduler and client.
Merge branch 'master' of http://code.dapps.douban.com/beanseye
remote debug build flag from Makefile.
Merge remote-tracking branch 'upstream/master' into optimize_scheduler
Merge pull request #39 from lilinghui/beanseye:optimize_scheduler

optimize the Makefile
fix the ut make is passed.