Add getByID() & getByHandle() to DataType & DataList

I want to load object more simple.
Merge branch 'Simple-initialization' of https://github.com/tao-s/Data into tao-s_function_helpers
Adjust DataType interface

- Remove contructor to avoid type juggling that may lead to sneaky bugs
- Change `getByID` and `getByHandle` to use ADOdb active record
  interface
- Add tests
Adjust DataList interface

- Change method `getByID` to `getByDataTypeID`
- Change method `getByHandle` to `getByDataTypeHandle`
- Adjust for remove DataType constructor method
- Add tests

Adding `DataType` to get methods to make it more clear as this is the
`DataList` class and did not want users to think this is getting the
`DataList` by id, handle
Merge pull request #20 from mkly/tao-s_function_helpers

Tao s function helpers