Soap upsert/update fails

Some other soap issues are as follows and semi-addressed in the following patch. This patch would only apply if the addition of the bundle property is added in here: http://drupal.org/node/1882342

1. Pushing a single object returns a single object- not an array. salesforce_push_process_soap_results() expects an array so a single result must be made iterable so it can run through the routine of creating a salesforce_mapping_object or reporting errors.
2. If pushing different kinds of sObjects in your payload, you must do so in separate upserts. The synced entities array that is passed to salesforce_push_process_soap_results() also needs to keep the same index.
3. We need to check if the salesforce_mapping_object exists in salesforce_push_process_soap_results() before creating it (this errors and terminates on processing an update)
4. If the bundle is added onto the salesforce_mapping_object table, we have to make sure that multiple entities using the same key (ie: a user entity and it's cooresponding profile2 entity) aren't in the same payload. In the case of users and profile 2 entities, the user would sync on the first cron run and the profile2 entity would sync on the subsequent cron run.