Add fix for compile error with multiple uses of peerid_type (uint64_t)
variable in lambda expression.
- known GCC issue: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65843
epee: replace return value of nullptr for expected boolean with false.
Fixes#231.
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
Javier Smooth