[BUGFIX] Clone response and re-process in Flux sub-Controller class

This bug fix addresses a problem with using the $this keyword from within FluxControllers; methods would be called statically and would be missing a class context. Fixed by cloning the response and using processRequest to execute the desired controller if the extension name is different from the host extension.
[TASK] Various cleaning in FluxService

It's cleaning time - fixing a few boolean/null comparison orders and implements a previously unified API method, having the side benefit of also respecting the cache in one additional case: when reading a list of available content areas from a content element by UID (which happens when pasting content elements).
[TASK] Remove a superfluous internal cache use
[TASK] Save a few µs by returning an array original instead of copy
[BUGFIX] Consider recursive array of values in cache key
[BUGFIX] Missing alt. CTypes in nested child content

Fixes: FluidTYPO3/fluidcontent/issues/40
Merge pull request #97 from NamelessCoder/servicecleanup

[TASK] Service cleanup: CGL, shifts to API, mini performance boosts
Merge pull request #95 from NamelessCoder/subrequests

[BUGFIX] Clone response and re-process in Flux sub-Controller class
Merge pull request #98 from NamelessCoder/issue/40

[BUGFIX] Missing alt. CTypes in nested child content