Merge pull request #926 from jails/feature/database-not-null

Add support for `IS NOT NULL` for SQL based datasouces, close #924
reset Session config after HMAC test to prevent it from disrupting other tests
fix Memcache adapter test.  when it encounters a key which doesn't exist it returns null, not false.  see \lithium\storage\cache\adapter\Memcache::read()
Merge pull request #927 from pixelcog/fix-tests

Quick Fix for Failing Tests
Merge pull request #919 from jails/refactor/query-type-attr

BC Break (minor): Fix collision on `'type'` option for `Query`.
Merge pull request #929 from jails/typo/fixes-spaces

Fixes typo according li3 coding standards.
Update composer.json to list `li3` command as a binary
Merge pull request #931 from mehlah/composer-li3-bin

Update composer.json to list `li3` command as a binary
HABTM Model relationship support for READ queries using `Database` datasources.
Save relations implementation.