Update core/MY_Model.php

There was no possibility to disable backticks in function '_set_where' but with this edit you can disable them.
Where clause in update_by now sent to the query_builder after validation
Use CI's model renaming to allow using the relationship as model name
Using relationship as model name, and using relationship for loading the model
Return empty result if query doesn't have any data

Current request 'relate' will return a array with related key but
nothing else, if called to match value with no data. This will result
in error to models extending base model.

This fix skip the 'belong_to' and 'has_many' call if no data was found.
Added only_deleted() scope

This allows you to get only the rows that are marked as 'deleted' in the
database, without getting the rows that aren't marked as 'deleted'.
"$this->_temporary_only_deleted === TRUE" seems stupid.
Fix to tests
Merge branch 'feature/only_deleted' of github.com:AKPWebDesign/codeigniter-base-model into AKPWebDesign-feature/only_deleted
Adjusting the soft delete conditions code - no need for multiple booleans
Adding tests for only_delete
Stripping out the set_database stuff. It's causing problems, is difficult to test and isn't used very often.
Merge branch 'master' of github.com:metagen/codeigniter-base-model into metagen-master
Merge branch 'master' of github.com:fzhan/codeigniter-base-model into fzhan-master
Typo in README
Adjusting the loading mechanism to make the tests pass and reduce conflicts
Merge branch 'fzhan-master'
Merge branch 'patch-1' of github.com:mrlnx/codeigniter-base-model into mrlnx-patch-1

Conflicts:
	core/MY_Model.php
removed unsed
changed order of Where for delete_by