Change salesforce download from git to dev snapshot

Originally I thought the git download would actually give you a git repo
which I thought would be useful for us, but it does not, so a dev snapshot
is just the same.
Adding patches we have developed for the salesforce module

Most are not currently located on Drupal.org because they need further
refinement before they would be accepted by ThinkShout, but we need to
start using them now.  Those on Drupal.org appear to have been accepted by
ThinkShout, but they have not committed them.