Revision
Fix memory leaks in Test_ORMObject
Make some relation-methods is const
Adapters for specific DBMS moved in a separate folder
Remove header initDB() in PostgreSQLAdapter
Some small changes and optimizations in ormtool
Now relations-methods returns 0 if no object associated with parent
model
Remove pluck() method from adapter, move this functional in find()
Now some ORMObject's methods returns 0 if no objects found
Update tests
Update documentation
Remove "calculation" methods without WHERE expression
Update tests
Update orm.h header