This fixes a double free that happens when calling cJSON_Delete on an
item that has been used by parse_string and it failed parsing the
string.

The double free happens, because parse_string frees an alias of
item->valuestring, but doesn't set item->valuestring to NULL.

Thanks @rrvirtual for the suggestion.

Introduce the cunity testing framework

Enabling this flag enables AddressSanitizer and
UndefinedBehaviorSanitizer

Test parsing and printing example files

git-subtree-dir: tests/unity
git-subtree-split: 1782bab0bacd349a45bc215ff91f082912cd7a64

Simplify some code and improve correctness

This might cause slight changes in behavior, but it shouldn't break
anything that is not already broken (for example the original macro
could either return a double, or an integer or whatever depending on if
object is NULL or not.)

Replaces the hand written floating point parser with the C library
implementation.

This reverts commit c866abd8.

The length of this buffer was intentional. This looks like a false
positive.

Use goto fail for error handling and fix some memory leaks on the way

Simplify error handling using goto fail and improve some names.

Makes the control flow easier to reason about and fixes a few potential
memory leaks.

Makes the control flow easier to reason about and fixes a few potential
memory leaks.

Makes the control flow easier to reason about and fixes a few potential
memory leaks.