add Salesforce API error handling for salesforce_bulk gem;

Salesforce bulk API isn't so descriptive in error messages as simple
salesforce API.
These changes add ability to run failed query through
databasedotcom-rails gem and raise error with informative description
about what's going on.

Error handling example, when we have bad query with wrong type in Conditions:
```ruby
Databasedotcom::SalesForceError: 
          WHERE Show_in_IDS__c = true and PublishStatus
                ^
ERROR at Row:5:Column:17
value of filter criterion for field 'Show_in_IDS__c' must be of type string and should be enclosed in quotes
```