Only set the password if it isn't empty.

git-svn-id: http://tortoisesvn.googlecode.com/svn/trunk@25934 4cfb86a4-2c7a-11df-bd14-c1e331e6ceac
Update issue #666
Use a separate SVN instance for every project update check to avoid using leftover authentication data.

git-svn-id: http://tortoisesvn.googlecode.com/svn/trunk@25935 4cfb86a4-2c7a-11df-bd14-c1e331e6ceac