Make svn password prompt available during setup.
Make svn password prompt available during setup.

Allow the user to interact with the svn password prompt
if needed.  Verify the svn server is reachable before
proceeding.  Clean extra UI issues up.  Readability
fixes.

BUG=none
TEST=prompted for a svn password if ~/.subversion/auth
is empty, bad svn server causes early timeout
Review URL: http://codereview.chromium.org/267059

git-svn-id: bd64dd6fa6f3f0ed0c0666d1018379882b742947@29552 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

svn2github/chromium-depot-tools,svn2github/chromium-depot-tools,svn2github/chromium-depot-tools