libjson-c: update to 0.16

libjson-c: update to 0.16

Fix:
- 001-dont-build-docs.patch

Remove upstreamed patch:
- 010-clang.patch

Changelog:

Deprecated and removed features:
--------------------------------
* JSON_C_OBJECT_KEY_IS_CONSTANT is deprecated in favor of
  JSON_C_OBJECT_ADD_CONSTANT_KEY
* Direct access to lh_table and lh_entry structure members is deprecated.
  Use access functions instead, lh_table_head(), lh_entry_next(), etc...
* Drop REFCOUNT_DEBUG code.

New features
------------
* The 0.16 release introduces no new features

Build changes
-------------
* Add a DISABLE_EXTRA_LIBS option to skip using libbsd
* Add a DISABLE_JSON_POINTER option to skip compiling in json_pointer support.

Significant changes and bug fixes
---------------------------------
* Cap string length at INT_MAX to avoid various issues with very long strings.
* json_object_deep_copy: fix deep copy of strings containing '\0'
* Fix read past end of buffer in the "json_parse" command
* Avoid out of memory accesses in the locally provided vasprintf() function
  (for those platforms that use it)
* Handle allocation failure in json_tokener_new_ex
* Fix use-after-free in json_tokener_new_ex() in the event of printbuf_new() returning NULL
* printbuf_memset(): set gaps to zero - areas within the print buffer which
  have not been initialized by using printbuf_memset
* printbuf: return -1 on invalid arguments (len < 0 or total buffer > INT_MAX)
* sprintbuf(): propagate printbuf_memappend errors back to the caller

Optimizations
--------------
* Speed up parsing by replacing ctype functions with simplified, faster
  non-locale-sensitive ones in json_tokener and json_object_to_json_string.
* Neither vertical tab nor formfeed are considered whitespace per the JSON spec
* json_object: speed up creation of objects, calloc() -> malloc() + set fields
* Avoid needless extra strlen() call in json_c_shallow_copy_default() and
  json_object_equal() when the object is known to be a json_type_string.

Other changes
-------------
* Validate size arguments in arraylist functions.
* Use getrandom() if available; with GRND_NONBLOCK to allow use of json-c
  very early during boot, such as part of cryptsetup.
* Use arc4random() if it's available.
* random_seed: on error, continue to next method instead of exiting the process
* Close file when unable to read from /dev/urandom in get_dev_random_seed()

Signed-off-by: Nick Hainke <vincent@systemli.org>