doctrine/doctrine2 — pull request #1133 by phansys (2014-09-12 00:18:43+00:00)
Title: [Embeddables] Improved exception message

Improved exception message when embeddable definition is missing 'class' attribute.
Instead of:
```
The class '' was not found in the chain configured namespaces ...
```
It shows:
```
The embed mapping 'embeddedname' misses the 'class' attribute.
```