More revisions to the code structure for Dropbox and GoogleDrive connectors, to establish best practices having to do with background thread structures and input streams.

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/trunk@1489686 13f79535-47bb-0310-9956-ffa450edef68
Again, more rearrangement.  This time make sure finishUp() is in a finally block, and merge it with abort().

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/trunk@1489689 13f79535-47bb-0310-9956-ffa450edef68
Output file path includes uri.getUserInfo().
Need to remove username and password from output file path.

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/trunk@1489696 13f79535-47bb-0310-9956-ffa450edef68