Remove AC_TYPE* from the libhdfs build since we get these via stdint.
Currently configure.ac uses AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T and AC_TYPE_UINT16_T and thus requires autoconf 2.61 or higher.
This prevents using it on such platforms as CentOS/RHEL 5.4 and 5.5. Given that those are pretty popular and also given that it is really difficult to find a platform
these days that doesn't natively define intXX_t types I'm curious as to whether we can simply remove those macros or perhaps fail ONLY if we happen to be on such
Here's a link to GNU autoconf docs for your reference: