Added "readOnly: true" to YAML reference

The readOnly configuration is documented nowhere except in the annotations reference.

I added it to the example, for a lack of a better place. But at least it will be documented somewhere.

Can you also confirm that this is correct? I'm starting to use it, and I can't find a way to have doctrine validate it is really working. Even with the metadata validation tool, it won't raise an error if I put an invalid entry (`readOnlyFOOBAR: true`) or an invalid value (`readOnly: FOOBAR`), so I'm kind of blind here.
Test EntityManager::createNamedQuery.
Test EntityManager::createNamedNativeQuery.
Add ability to test same parameter name for multiple values.
Changed logic to allow joining games, and becoming friends

Added Spacing
mention SQL Anywhere in basic mapping docs
Merge pull request #860 from deeky666/add-sql-anywhere-documentation

Mention SQL Anywhere in basic mapping documentation
Merge pull request #849 from bsahlhof/master

Error with Same Field, Multiple Values, Criteria and QueryBuilder
Added a note about changing the fetch mode for to-many relations
Merge pull request #862 from stof/patch-2

Added a note about changing the fetch mode for to-many relations
Mentioning the 'refresh' cascading property in the documentation list
Merge pull request #866 from bountin/doc_refresh

Mentioning the 'refresh' cascading property in the documentation list
Added documentation section for Memcached
Merge pull request #868 from mnapoli/patch-1

Added documentation section for Memcached
Documenting interface methods (based on entity manager)
Fixing FQCN on docblox
Use docblox from EntityManagerInterface
Merge pull request #870 from lcobucci/master

Documenting interface methods (based on entity manager)
XCache cannot be cleared on CLI (like APC)
XCache cannot be cleared on CLI (like APC)
XCache cannot be cleared on CLI (like APC)