Event: added ordering to query
svn: Fix failure of commit by a client using serf

A response to HEAD request MUST NOT have a body.
Merge branch 'fix/svnkit-commit' of dlab/hive

from pull request 1146
Merge branch 'bugfix/issue-1535' of dlab/hive

from pull request 1150
Fix a typo; aabel -> label
Merge branch 'fix/typo-aabel' of dlab/hive

from pull request 1153
Add the release notes for v0.5.7.
Merge branch 'docs/relnotes-0.5.7' of dlab/hive

from pull request 1155
Yobi 0.5.7

It is the seventh maintenance release of Yobi 0.5.

This includes two major bug fixes; SVN commit bug and incorrect ordering
of event list in the main page.

Reviewed-by: Suwon Chae <doortts@gmail.com>