Merge tag 'v2.11.0'

2.11.0
fix skipping async validator will always fail if condition is un-fulfilled

If the validator configured with `{async:true}` option and `if/unless`
condition, validator should be skipped when the condition is un-fulfilled,
so the validator should be pass.

But currently, when skipping the validator, it calls `done(true)` which
accepts a `fail` flag as a param, this will fail the entire validation.

Signed-off-by: Clark Wang <clark.wangs@gmail.com>
Allow hasOne relation to have a scope option

Signed-off-by: Clark Wang <clark.wangs@gmail.com>
Merge pull request #356 from clarkorz/feature/allow-scope-hasone

Allow hasOne relation to have a scope option
Be explicit: set RelationDefinition multiple flag
fix embedsOne error when embed instance is undefined or null

Signed-off-by: Clark Wang <clark.wangs@gmail.com>
Merge pull request #357 from fabien/fix/rel-multiple

Set RelationDefinition multiple flag
Update README.md
docs.json: add lib/model.js
Fix a typo
Allow more flavors of nullable values from DB discovery
Merge pull request #354 from clarkorz/fix/skip-validation

fix skipping async validator will always fail if condition is un-fulfilled
Merge pull request #360 from clarkorz/fix/embedsOne-errors

fix embedsOne error when embed instance is undefined or null
Merge pull request #364 from strongloop/feature/include-base-model-in-apidocs

docs.json: add lib/model.js
Relax the id comparison
v2.12.0
Merge branch 'release/2.12.0' into production