Flexible cHash Calculation

Introduces new configuration options for $TYPO3_CONF_VARS['FE']
* cHashRequiredParameters
* cHashExcludedParameters
* cHashExcludedParametersIfEmpty
* cHashOnlyForParameters

Moves the adjusted cHash calculation logic to it's own class
t3lib_cacheHash.

Change-Id: I257ddd2042015622872519db18deee1b5071f950
Resolves: #29365
Releases: 4.7

Conflicts:
	t3lib/core_autoload.php

Signed-off-by: Marco Milojevic <marco.milojevic@ws-116.aoemedia.lan>