fixe int32_t definition for VC11

int32_t is nowhere in msvc, so the version check could be even removed
snprintf definition is needed here, too
Fix C89 compat needed by MSVC
Fixes for Infinity and NaN

Although JSON RFC does not support NaN or Infinity
as numeric values ECMA 262 section 9.8.1 defines
how to handle these cases as strings
in strick mode, number must not start with 0
Merge pull request #88 from weltling/master

Several MSVC fixes
Merge pull request #89 from ayanes/master

Support NaN and Infinity
Merge pull request #90 from remicollet/issue-strict

in strick mode, number must not start with 0
Minor spell check.
Mention that libtoolize is needed if you're not using a release tarball.
Fix the _MSC_VER check so it compiles on non-windows compilers.  Issue#91
Issue#84: explicitly remove old headers and include/json directory so creating the compat symlink can work.
Eliminate use of MC_ABORT in json-c code, and mark MC_ABORT/mc_abort deprecated.
Also adjust an error message in json_util to make it unique.  Fixes #87.
fixing problem that isinf(-Inf) can be 1 or -1