Fix afterFind() called twice with hasMany relationship

It occurs when a model and the children models are related to a same model.
For example, such as the following:

* User hasMany Comment
* User hasMany Article
* Article hasMany Comment
Fix different format of $results in afterFind

Refs #2529

As of this commit, we can get consistent format of $resutls in afterFind.
And we can keep backward compatibility if Model::$useConsistentAfterFind is set to false.
Ignore RuntimeException

RuntimeException is thrown at race condition.
However, since for the processing at Garbage Collection, other processes
is determined that the expired.
this process is acceptable to ignore the RuntimeException even if there is
missing file.
Merge pull request #4304 from mtak3/ignore_exception_cache_file_engine

Ignore RuntimeException
Optimize FileEngine::gc()

SplFileObject constructor throws an exception if the file does not exist or is a directory.
Merge pull request #4322 from majna/master-file-engine

Optimize FileEngine::gc()
HttpSocket: not overwriting auth header if it is set in request configuration
Merge pull request #4331 from jeremyharris/master

Fix HttpSocket multiple auth requests
Preventing multiple iterations
Merge pull request #4353 from karmicdice/patch-1

Prevent infinite loops by rendering a flash element inside a flash element.

Fixes: #4350
Fix 0 index not being properly parsed for files.
Merge pull request #4357 from bcrowe/3.0-CS

3.0 - Fix CS errors
A few random improvements to the database layer
Add test for #4309

The Router internals don't handle // which is good.
Merge pull request #4361 from cakephp/3.0-random-database-improvements

A few random improvements to the database layer
Generating true random v4 UUIDs.

This also makes the String::uuid() 3 times faster
Specifying the uuid version we generate
blacklist getOptionParser to prevent:

	Console/cake orm_cache<tab>
	build            clear            getOptionParser
Merge pull request #4365 from AD7six/3.0-blacklist-GOP

blacklist getOptionParser
Merge pull request #4362 from cakephp/3.0-random-uuids

Generating true random v4 UUIDs.