support for int/bigint arrays

[jogramming]

I was trying to use this but ran into issues with some of my columns having int and bigint arrays, tried to also hack around it by implementing FromValue myself but ran into more issues with Array::Int being only 32bits.

[ckcks12]

https://github.com/ivanceras/rustorm/blob/master/crates/dao/src/value.rs#L81-L103

I found it too. I'm curious about why he commented them out.