Implemented automatic tests for inspectdb and tests on the reimported model.

This test can be run only manualy by tests/inspectdb/test.sh
Only for Django >= 1.5, because our inspectdb can not prevent related_name
clashes at Django 1.4 and requires manual editing.
Fixed test for inspectdb (slow_test) for Django 1.7. and improved.
Fixed error with "manage.py test --verbosity=2" in Django 1.7+

Django 1.7+ uses migrations internally if the verbosity is high.
Migrations in tests can not be disabled by old settings for South.

Conflicts:

	salesforce/testrunner/example/models.py
Fix a test for multiple databases for different sf_alias.
Fixed deprecation warning: renamed get_query_set to get_queryset.
Fixed whitespace/tabs
Comments on DatabaseFeatures, related settings.
Tests for old known unfixed bugs (skipped with a message)
Added automatic db_column detection from the field name in most cases.

Also "__c" is added to custom fields  marked by the parameter "custom=True".
See examples in the test test_auto_db_column.

I use prefer the name "custom" of the parameter in user interface and
the name "sf_custom" for equivalent attribute in the class hierarchy,
though the parameter "sf_read_only" name was both with "sf_".I use names
"sf_* in Django objects internaly more frequently to prevent possible future
clashes. In the user interface I use "sf_" only where it helps to better
readability if a similar name exists already somewhere in Django.
Modified tests to verify the automatic names with Django conventions.

All fields in example Contact renamed to lowercase. Updated tests.
Support for column names in custom models and namespaces of managed packages.

Implemented attribute "custom" in Meta class of custom models.
Support for automatic db_column with:
- standard fields in custom objects (e.g. LastModifiedDate)
- custom fields in standard objects
- namespaces from Salesforce managed packages
Added test and docs for custom objects and namespaces.
Fixed some less readable field names in testrunner example models. Added m2m.

Added m2m example model Opportunity. (not used yet)
Test for custom model with some standard and some custom fields.

Database columns are connected without any special parameter about '__c' etc.
Supported configurable primary key name id/Id.
Fixed README.
Temporary patches for tests.

It should be used so: It is temporary applied now on whenever in the future and
tests are run with it.
Implemented reconstruction of original CamelCase SF class names by inspectdb

Inspectdb has never produced nice class names, e.g. it was only
"Accountcontactrole" instead of "AccountContactRole", until fixed now.
Not implemented for Django 1.4, because impossible.
Added default=True to BooleanField.

Salesforce has everytimes a default value for the Checkbox field: Checked or
Unchecked (default for default).
Added option --table-filter=TABLE_NAME_FILTER to inspectdb.

See modified README.