Remove left over ElementCollection code.
Fix non initialized association proxy
Merge pull request #883 from FabioBatSilva/hotfix-slc

[DDC-2862] Fix non initialized association proxy
Fix cache misses using one-to-one inverse side
Merge pull request #884 from FabioBatSilva/slc-patch1

[SLC] Fix cache misses using one-to-one inverse side
Add an example to doc of YAML mapping
Merge pull request #888 from entering/docs-yaml-mapping-improve-example

Add an example to doc of YAML mapping
Merge branch 'master' of https://github.com/doctrine/doctrine2 into lifetime-cache
Add doc