On 32-bit MinGW-w64, time_t is int32_t. The existing code was serializing
time_t directly and implicitly assuming that time_t is int64_t. This commit
formalizes that assumption by serializing int64_t directly and casting to
time_t where appropriate.
Thanks go to greatwolf for reporting this issue.
monero-project/bitmonero#88
Per my reading this change makes sense since a subset of the exclusive
peers could be priority peers. Priority peers that are not exclusive
will not get loaded, and priority peers that *are* exclusive will get
special treatment. Prior to this change it looks like priority peers
were silently ignored when exclusive peers were provided.