Port Little Endian specific code

[reeteshranjan]

Since there are no network to host and vice versa conversion functions for 64-bit, the __bswap64 macro/function is directly used to work these types byte ordering conversion between nginx and sphinx. Need to detect the endianness and then perform such swaps if required. Basically, introduce something like ntoh64 and hton64 that internally use __bswap64 as required.

Target file: ngx_http_sphinx2_stream.c