1) Prefer SVN to GIT when examining a repository
2) Adds an extra check for a Git repository to make sure that it contains an SVN repository within it.

Review by: ispeters,scottb


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@5263 8db76d5a-ed1c-0410-87a9-c151d255dfc7