32bit time and Year 2038 problem

[dram]

While doing PR #100, I found that Self using 32bit time representation. As it will suffer from Year 2038 problem, I think it need to be fixed.

[dram]

According to Wikipedia:

Linux uses a 64-bit time_t for 64-bit architectures only; the pure 32-bit ABI is not changed due to backward compatibility.

It seems that it's not easy to support 64-bit time in 32-bit Self, so maybe making Self support 64-bit system is the first to do.