Revert "[TASK] Replace inject methods with @inject; allow @Flow\Inject"

This reverts commit ad7219c2818455edd65918b9a5f8d1b70c0afed7

See https://review.typo3.org/#/c/21997/

More notes on this:
A regex to replace @inject with @Flow\Inject when porting 
Extbase extensions to Flow is very simple and fast.

Additionally @Flow\Inject makes only sense with using "use 
TYPO3\Flow\Annotations as Flow". But with a backported 
annotation parser I expect that we would have annotations 
in "TYPO3\CMS\Extbase\Annotations". Using them as alias 
"Flow" is a bad style as the alias should be "Extbase" then.

Change-Id: I2113b5320f2a6f5dd56cfa7b06469fa1628d2645
Reviewed-on: https://review.typo3.org/22004
Reviewed-by: Marc Bastian Heinrichs
Tested-by: Marc Bastian Heinrichs
Revert "[FEATURE] Support @Flow\Inject annotations in Extbase"

This reverts commit 09bc492925713036cef679c92ffc28eda941605c

We should not support this annotation in extbase, because it 
has no benefit and breaks with the annotation concept in 
Flow. "Flow" is only an alias for "TYPO3\Flow\Annotations" in 
Flow and needs to be registered by "use TYPO3\Flow\Annotations as Flow".

Change-Id: Ic0ecdc58754c176b1140db463c2405cb47bf9933
Reviewed-on: https://review.typo3.org/21997
Reviewed-by: Marc Bastian Heinrichs
Tested-by: Marc Bastian Heinrichs