A macro named `ENABLE_LOCALES` was added and an option with the same name too in the CMakeLists.txt

pointer in error case and change code to match new expectations.

If realloc returns NULL, ensure didn't abort but returned
printbuffer.offset instead. If an attacker can control
printbuffer.offset and also make realloc fail at just the right moment,
this would make cJSON potentially write at an arbitrary memory address.

This has been detected via MSVC's Warning C4668

C89 sadly doesn't provide safe alternatives for strcpy, sprintf and the
like.

Also fixes a potential memory leak

It did consider two arrays equal if one is a subset of te other one,
which is incorrect.

See #180

It did consider two arrays equal if one is a prefix of the other one,
which is incorrect.

See #180