#DDC-2664 Document new Proxy factory flags usage as of DCOM-210

[Document new Proxy factory flags usage as of DCOM-210](http://www.doctrine-project.org/jira/browse/DDC-2664)
#DDC-2664 Improving and fixing documentation for new Proxy factory flags usage as of DCOM-210
Merge pull request #782 from mnapoli/patch-4

#DDC-2664 Document new Proxy factory flags usage as of DCOM-210
Move Annotations introduction to the reference.
Refactor Basic Mapping chapter to focus on the actual topic more. Rearrange apperance of topics. Introduce a sane example entity as example.
Move Custom Mapping Types into cookbook, restructure the chapter more.
Small fixes in basic-mapping.rst
Fix some more details in basic-mapping.rst
fix warnings p1

fix warnings p2

fix warnings p3

fix warnings p4
Merge pull request #784 from eventhorizonpl/fix_docs

fix documentation warnings p1
Update dql-custom-walkers.rst

Fixed typo of "customer" to "custom"
Merge pull request #785 from Hawkeye0203/patch-1

Update dql-custom-walkers.rst
Delete some very old, leftover code.
Fix master dependening on DBAL 2.5-dev
Minor updates while reading the basic-mapping page

The only arguable changes involve a few spots where I either removed something I thought was too technical and not valuable (e.g. talking about the metadata mapping pattern).
Changes thanks to @Ocramius
Merge pull request #786 from weaverryan/patch-1

Minor updates while reading the basic-mapping page
HHVM compatibility: func_get_args

All func_get_args() calls have been moved to the top of the methods
because HHVM doesn't keep a copy of the original args for performance
reasons.

See facebook/hiphop-php#1027 for details.
Merge pull request #790 from javer/hhvm-func_get_args

HHVM compatibility: func_get_args