Add definition lookup for attr(), belongsTo() and hasMany()

[Turbo87]

[locks]

bors r+

[ghost]

AppVeyor is building the staging.tmp branch.
This is not necessary.
It wastes time, and makes your build and everyone else's slow.

To do this, you can add this to your appveyor.yml file,
if you only care about pull requests, staging, and trying:

branches:
  only:
    - master
    - staging
    - trying

Alternatively, you can add this to only turn off staging.tmp:

branches:
  except:
    - staging.tmp

[ghost]

AppVeyor is building the staging.tmp branch.
This is not necessary.
It wastes time, and makes your build and everyone else's slow.

To do this, you can add this to your appveyor.yml file,
if you only care about pull requests, staging, and trying:

branches:
  only:
    - master
    - staging
    - trying

Alternatively, you can add this to only turn off staging.tmp:

branches:
  except:
    - staging.tmp

[ghost]

Build succeeded

• continuous-integration/travis-ci/push