switch from boost int types to <stdint.h>
json_spirit: #include <stdint.h>
removed a few unnecessary casts
Merge pull request #4129

d56e30c removed a few unnecessary casts (Kamil Domanski)
3e74ac2 json_spirit: #include <stdint.h> (Kamil Domanski)
4b61a6a switch from boost int types to <stdint.h> (Kamil Domanski)
remove ParseString(...) which is never used