cmake rules matters, and fix compile warnings now that we're building
those sources with all the regular flags.

This causes previously failing strings like "123-456" to return a valid json_object with the appropriate value.  If you care about the trailing content, call json_tokener_parse_ex() and check the parse end point with json_tokener_get_parse_end().

Deprecate the json_parse_double() function from json_util.h

Add an optional way to use an incremental chunk size ($TEST_PARSE_CHUNKSIZE)
for all of the single_basic_parse tests, in additional to the regular way.

Fix compiler errors and warnings when building on IBM operating systems such as AIX and IBM i.

validate utf-8 string

cc -DHAVE_CONFIG_H -I. -I..  -I.. -I../tests    -O2 -pipe  -fstack-protector-strong -fno-strict-aliasing  -Wall -Werror -Wcast-qual -Wno-error=deprecated-declarations -Wextra -Wno-unused-parameter -D_GNU_SOURCE -D_REENTRANT -MT test_parse.o -MD -MP -MF .deps/test_parse.Tpo -c -o test_parse.o test_parse.c
test_parse.c:256:14: error: adding 'int' to a string does not append to the string [-Werror,-Wstring-plus-int]
        { "null123" + 4,       4, 3, json_tokener_success, 1 },
          ~~~~~~~~~~^~~
test_parse.c:256:14: note: use array indexing to silence this warning
        { "null123" + 4,       4, 3, json_tokener_success, 1 },
                    ^
          &         [  ]
test_parse.c:258:12: error: adding 'int' to a string does not append to the string [-Werror,-Wstring-plus-int]
        { "nullx" + 4,         2, 0, json_tokener_error_parse_unexpected, 1 },
          ~~~~~~~~^~~
test_parse.c:258:12: note: use array indexing to silence this warning
        { "nullx" + 4,         2, 0, json_tokener_error_parse_unexpected, 1 },
                  ^
          &       [  ]
test_parse.c:260:25: error: adding 'int' to a string does not append to the string [-Werror,-Wstring-plus-int]
        { "{\"a\":1}{\"b\":2}" + 7,
          ~~~~~~~~~~~~~~~~~~~~~^~~
test_parse.c:260:25: note: use array indexing to silence this warning
        { "{\"a\":1}{\"b\":2}" + 7,
                               ^
          &                    [  ]
3 errors generated.
*** Error code 1

Stop.

Add several additional test cases for partial parsing of infinity values.

Also, emit the input string in the output so it's easier to see what's going on.

Some badly formated "numbers" could get partly parsed,
resulting in truncated results instead of raising an
error.

Examples :
 '1.2.3'      -> (double)1.2
 '2015-01-15' -> (int)2015

This patch is not perfect (ex: input can still end with a 'E', which
is forbidden by json.org doc) but should avoid non-sensically
formated input.

Tests added.