json patch: adding to a subfield of a non-object now fails as expected

Release 1.7.4

If the `string` property of the item that is added is an alias to the
`string` parameter of `add_item_to_object`, and `constant` is false,
`cJSON_strdup` would access the string after it has been freed.

Thanks @hhallen for reporting this in #248.

CMAKE_INSTALL_FULL_... needs to be used.

Release Version 1.7.1

Thanks @liuyunbin for reporting this in #230

Thanks @liuyunbin for reporting this in #230

Thanks @liuyunbin for reporting this in #230

Release Version 1.7.0

New documentation

Convert cJSON_Add..ToObject macros into functions with return values

These functions return the added object. Functions to add objects and
arrays have also been added.