Convert the svn hook to new api

Review Request #3909 — Created Feb. 24, 2013 and submitted — Latest diff uploaded

Information

Review Board
master

Reviewers

the svn commit hook to set a review request submitted only worked with the pre 1.6 api.
This patch makes it work with the new api.

It drops support for the old api.
Tested on my private setup with reviewboard 1.7.4 and subversion 1.7