Documentation for the abstraction layer
Merge pull request #183 from jcroll/abstraction_layer_docs

[RFC] Documentation for the abstraction layer
Merge branch '2.0'
Update config.rst

Adding undocumented config directive to indicate database name. This is discussed in DoctrineMongoDBBundle/issues/191
Composer should only update current dependency

Executing composer update will update all composer dependencies which can lead to undesired dependencies upgrades.

Instead, we should only call composer for update the desired packages
Merge pull request #207 from rodrigodiez/patch-1

Composer should only update current dependency
Fixed typo
Merge pull request #210 from gquemener/patch-1

Fixed typo
FormBuilderInterface documentation update 

use Symfony\Component\Form\FormBuilderInterface; instead 
Symfony\Component\Form\FormBuilder makes tutorial work with actual Symfony version
Merge pull request #211 from manuelkoch/master

FormBuilderInterface documentation update
Merge pull request #200 from lordnynex/patch-1

Document db connection option
Fixed Doctrine ODM basic mapping link
Merge pull request #217 from rodrigodiez/patch-2

Fixed Doctrine ODM basic mapping link
Allow any any options for connections in Configuration

Changed VariableNode to prototyped ArrayNode

Listing all options for connection in Configuration

Removed \MongoClient consts

Changed readPreferenceTags to arrayNode
Added full XML configuration and adjusted everything for it to pass
Fix Connection option config parsing

Also refactors the ConfigurationTest class. Removed strict checking of default_commit_options (and tests), added missing options. Fixed handling of readPreferenceTags option for XML.

As a change, "server" and "options" no longer have default values; however, existing code in Configuration should handle this fine.
Clean up XML and YML config fixtures
Use boolean config type for "auto_mapping" option
Update XSD to match Configuration class
Do not skip tests if mongod, PECL driver, or ODM is unavailable