We assume that merging is done into copy of global config which is always set to not null value.
It contains the default values.
Parameters: currentConfig -
Merges global settings with local ones.
General rule is: local settings override the global ones.
The only exception is 'disabled' flag: 'disabled' is true if any of the disabled flags
(global or local) is true.
Parameters: globalConfig - global config is normally set on the cache factory Parameters: localConfig - is supplied when registering cache in cache factory merged OdalCacheConfig