Fixed handle_api_exceptions more according to docs. Fixed possible errors during session ID expire.

- Some errors after session ID expire could were silenty shaded by it.
  All errors from SF API or network request shoudl be now reported as
  'SalesforceError' with an appropriate exception message.
- The code can be now better organized according to SF API, not by restkit
  exception codes, as was before.
- Amount of printed information about error states is still too in-depth.
Support for silenced error messages during tests that must raise exception.

The setting is related to a query, thus debug messages are soon reenabled.
Added support for "queryAll" requests, including deleted objects, new in API 29.0
Added test for big queries that are being splitted to more requests.
Added test that a request with invalid/expired auth ID re-authenticates and succeeds.
Changed minor texts
Updated the example testrunner project to new Django and for general SF models.

Added browser tests that pass for Django 1.4..1.7
Merge pull request #41 from hynekcer/fix_api_exceptions

Fixed handle_api_exceptions + many additions