Seems to perform better than outputting to string
and re-parsing it.

BENCHMARK - 1000000 iterations of 'dst2 = json_tokener_parse(json_object_get_string(src2))' took 20 seconds
BENCHMARK - 1000000 iterations of 'dst2 = json_tokener_parse(json_object_get_string(src2))' took 7 seconds

It should make a difference on embedded systems.
The test was performed on a i5 desktop CPU [~3.5 years of age].

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Issue #338, add json_object_add_int functions

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.

OSX) always include the _json_c_strerror function but only enable it with a flag
 during tests.

If we want to override `strerror()` in libjson-c
to make tests consistent across platforms, we
need to do it build-wide as configure/build
option.

Apple linkers make it really hard to override functions
at link-time, and this seems to be locked down on travis-ci.org
[ for security reasons I assume ].
While I got it to work locally, it did not work
when running on travis.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Which now seems to fail the build.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

More code compression/de-duplication.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Add a test that triggers the problem to ensure it stays fixed.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Also, there's no need to worry about output consistency here, since it'll be
 different anyway due to different pointer values.

Improve json_object -> string performance

Hawciz pointed out that the previous commit modifies the public
interface of printbuf. Per his suggestion, sprintbuf() was restored
and a new pair of macros was added that wraps printbuf_memappend().

Using a wrapper macro instead of modifying sprintbuf() also reduces
function call overhead, bringing total performance gains to
approximately 400%.

Removes variadic prints for ~3x performance improvement.

closes https://github.com/json-c/json-c/issues/278

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

I got this on Mac OS X at least.
Not sure if it shows up in other envs

error:
```
strerror_override.c:53:13: error: incompatible redeclaration of library function 'strerror' [-Werror,-Wincompatible-library-redeclaration]
const char *strerror(int errno_in)
```

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Json object set xxx