Revert "[FEATURE] Added Ajax JSON Memcache"

This reverts commit bd8796b824d2e88d91be07bea0284ca25f1d2a45.

It turns out it's pretty much useless as long as the data passed to
get_json is not also being cached.
Merge branch 'issue-444-theserapher' of github.com:TheSerapher/php-mmcfe-ng into issue-444-theserapher