Fix most of the issues reported by the Visual Studio code analysis tool

9ecd703 Merge pull request #39 from mr-mixas/test-absent-from-location-for-copy-and-move-ops
66817e7 test absent 'from' location for copy and move
09dee56 Fix anonymous test
8bae8ed Fix « test should pass - no error » test
855f2a4 Fix « test should pass despite (nested) rearrangement » test
53283fc Fix « test should pass despite rearrangement » test
ecf01e7 Fix « null value should be valid obj property » test
1586cdf Fix « Empty-string element » test

git-subtree-dir: tests/json-patch-tests
git-subtree-split: 9ecd703c08cda4864cd2d2fb580a513ec5740934

Support default __stdcall calling convention (/Gz) on Windows

Thanks @AlfieDeng for reporting

fix a typo in cJSON.h

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.